Repairing the Whirlpool and KitchenAid Ice Machines


 
Inevitable Problems and How To Fix Them
 
Do It Yourself
OR
Know What Your Service Technician Should Be Doing
 
Where to Find Parts and How Much They Should Cost
 
Detailed Instructions Below on Troubleshooting, Diagnosis, and Repair
 
Written by the world's biggest fan and aficionado of these machines.

I last updated this page: March, 2014.
My first edition was: April, 2004.

The under-counter Whirlpool ice machine is a stand-alone $1700 appliance which makes gourmet clear ice such as for a wet bar. (Yes, that is what it originally cost in today's dollars before the current era of cheaper imported appliances.) It has occasionally been labeled and sold as Sub Zero, Scotsman, GM/Frigidaire, KitchenAid, Estate, Roper, Inglis, Ross Temp, Marvel, and Sears Kenmore brands, and is similar in quality and specifications to the under-counter Jenn-Air 50 lb/day ice machines currently sold. This luxury ice machine should not be confused with the ordinary ice maker that is part of a refrigerator-freezer; the former magnificent engine makes crystal-clear, flavor-free, ice cubes. A refrigerator-freezer ice maker produces cloudy ice in a stale-garlic flavor, typically in odd crescent shapes, and stuck together. The ice machine's product is clear, pure, flavorless ice cubes which are luxuriously wet and loose, like a handful of flawless diamonds scooped from a mountain spring. Owning this machine once in your life will spoil you, like many of my correspondents who say they will never again return to refrigerator ice.

Besides this delicious indulgence, the ice machine also makes an excellent source for controlled cold-plate chilling necessary to the operation of an even greater luxury, the home soda fountain (see my page on home carbonation). On this page, however, we are only concerned with the ice and how to keep it coming.

This residential ice machine creates 8 x 7 x 1/2 inch slabs of ice by recirculating water over a metal evaporator plate chilled by an R-134a chiller (or R-12 before the early 1990s; this basic machine design goes back to the 1950s). When a slab of ice reaches the finished thickness, a thermostat triggers the harvest cycle, which reverses the chiller to warm the evaporator plate, until the ice slab slides onto a cutter grid. The cutter grid consists of nickel-chromium ("Nichrome" is one brand) resistance wire which is warmed by a low-voltage electric current. The ice slab rests on the heated wires, and the wires slice through the slab, first in one direction on the top layer of wires, then the perpendicular direction on the lower layer, yielding cubes of ice which drop into an insulated ice supply bin.

The original machines were produced in an 18-inch width for a standard 34.5-inch under-counter height. Since 1999 a 15-inch version is also available.

The only part of this machine which chills is the evaporator plate at the top of the machine where the ice forms. Unlike a conventional refrigerator-freezer, the ice storage bin is only insulated. The air inside is not refrigerated, and the temperature never drops below freezing. This bin is more or less like a portable ice chest but built into the cabinet. This is an essential principle of a wet ice machine. The cubes stay loose and are always slowly melting, so the machine runs to make new ice to keep the bin filled and to make up the ice you withdraw for use.

I got to know these machines quite well over the last 14 years. In 1995 I moved into a home equipped with one, and learned about this unusual appliance by doing my own repairs. It eventually became an essential part of my home carbonation and soda fountain efforts (see link above).

Then in 2002, I wound up owning a truckload of them, after I went to the bankruptcy auction of the infamous Enron accounting firm, Arthur Andersen, where I had expected to buy various assets for my computer business. Their corporate skyscraper suites were furnished with a large quantity of these machines, recently purchased. While I wanted to buy one to have as a spare, the auctioneer abruptly insisted on selling all of them as one lot. Of course, nobody else at a business-equipment auction wanted such a haul, but I saw an opportunity, knew what I was dealing with, and took them all for 5 cents on the dollar. I made a terrific profit reselling them one-at-a-time on eBay (sorry, they're all gone now), but in the process I had to become expert at diagnosing and repairing them, using my engineering background. This experience also allowed me conclude what were the more common problems and led me to create this Web page. Having maintained this Web page for some years, I have corresponded with hundreds of other ice machine owners, and performed (or at least consulted on) most all of the repair problems presented by these machines. Below you will find the accumulated wisdom for diagnosis and repair procedures, obtaining original parts, improvising ersatz parts, and dealing with service technicians.

The photos here show my personal unit made in 1997, model EC5100XFB0. The essentially identical machine has been sold for years and years under a variety of brands, model numbers, and styles of decor. Other than a change away from R-12 refrigerant to R-134a about 1992, and a change from electromechanical controls to computerized electronics about 2002, the principles, components, and physical arrangement have been the same for many decades. An excellent source of information, including parts diagrams, parts catalog, and pricing is available at partselect.com and at sears.com, even if they're not the best place to buy parts. You can enter your specific model number there and compare the parts involved in your repair to those specified for mine.

Similar models include: ACS50 ACS501 ACS502 CCS51AEL CECS2AE1 CHCS51AE1 CSWE1 CSW1AE CSW1AE1B5 CSW45 CSW45PA1B0 (Scotsman) EC5100 EC5100XEB0 EC5100XEB1 EC5100XEN0 EC5100XEN1 EC5100XEW0 EC5100XEW1 EC5100XFB0 EC5100XFB1 EC5100XFN0 EC5100XFN1 EC5100XFW0 EC5100XFW1 EC5100XL EC5100XP EC5100XT EC5100XT1 EC510BXD0 EC510NXD0 EC510WXD0 EC510WXE0 EHC511 EUC050A1 ZDI15 ZDI15CBB GI1500PHB0 GI1500PHB3 GI1500PHB6 GI1500PHW0 GI1500PHW3 GI1500XH GI1500XHB0 GI1500XHB1 GI1500XHB2 GI1500XHB3 GI1500XHN0 GI1500XHN1 GI1500XHN2 GI1500XHN3 GI1500XHS0 GI1500XHS1 GI1500XHS2 GI1500XHS3 GI1500XHT1 GI1500XHT2 GI1500XHT3 GI1500XHW0 GI1500XHW1 GI1500XHW2 GI1500XHW3 GI1500XHW7 GI15NDXTB GI15NDXTS GI15NDXXS GI15NFLTS0 GI15NFRTB0 GI15NFRTB1 GI15NFRTB2 GI15NFRTB3 GI15NFRTB4 IACS501 IACS50E1 JEAC501 JEAC50SL0 JEAC50SL1 JEACS50SL0 JEACS50SL1 JLAIC5053 JT051CAE1612 JT051CAE2511 JT051CAE2512 JVGC535A0 JVGC535A1 JVGC535W2 KUIA15NLH KUIA15NRH KUIA15PLL KUIA15PRL KUIA15RRL KUIA18NNJ KUIA18NNJS5 KUIA18PNL KUIA18PNLS1 KUIS155H KUIS155HLS3 KUIS155HRS3 KUIS15NRH KUIS15PRH KUIS185J KUIS185JSS0 KUIS185JWH2 KUIS18NNJ KUIS18NNJW5 KUIS18NNTW1 KUIS18PNJ KUIV18NNM O53CAE1610 O53CAE1612 RC-50-SC (Ross Temp) ZD115CBBE ZDIS15CSS (GE Monogram) 198.887482 106.86482690 106.86482691 198.8814831 3KUIS185V0 501-ISC (SubZero) JIM1550ARW JIM158XBRS JIM158XBRSO (Jenn-Air)

My trusty unit shown at left is still running after all these years. I have had to: repair the grid several times, replace the harvest thermostat with an electronic timer, replace the water solenoid valve, and recharge the unit with refrigerant. The basic refrigeration mechanism is very sturdy and reliable. Other owners of these machines have 30-year-old specimens still running.

Before you go off ordering expensive parts, or rashly discarding a failed unit, see if my information below can't help you diagnose and repair the trouble more economically. Let's first discuss the three most common problems that likely brought you here in the first place. After that, we'll detail the universe of rarer problems.

As wonderful as this machine performs, there are three chronic problems with Whirlpool's otherwise excellent design resulting in very costly repair calls, typically after only a few years of constant operation:

Not only do these problems suggest a house call from an appliance service, but these service calls can be very expensive. Ice machines are relatively rare items, and the expertise to diagnose and repair them tends to command a premium price, as do the manufacturer's sole-source parts. More typically, you're likely to get someone who may know how to fix a common refrigerator, but doesn't understand ice machines well enough to diagnose their unique types of problems.

If you're like me, you may find that you can perform a costly repair yourself, at minimal expense. What you need is some information and diagnostic analysis, which is why I wrote this Web page. Some repairs I'll describe may be beyond your abilities, but even if you're not a do-it-yourself'er, you can use this information to make a firm diagnosis yourself. At the very least, you will be able to critique whether a service technician is giving you a correct diagnosis and a fair price for repairs. In the grim case where your machine is not worth fixing, you can decide this without having to pay for a service call. I have published this information as part of my machine shop pages, because these repairs have to do with metal itself (nickel-chromium wire, solder), or with parts or suppliers closely associated with metalworking, even though there is no actual machining involved.


Understanding the Unit via Service Manuals

Before you attempt to diagnose or repair a problem, you may wish to study some of the service manuals I've been able to collect over the years. Different manuals cover the various designs and models from the 1970s to the present, so pick the manual(s) for the type of machine you have:


Repairing the Ice Cutter Grid

If your cutter grid breaks, the replacement part (326566 Grid Assembly) will cost you $224.75 from Whirlpool (2008 pricing), perhaps on top of a service call expense if you didn't diagnose the problem yourself. Yet this is an easy problem to diagnose, and perhaps even fully repair, yourself. The defect is repairable by replacing about 18 feet of a certain gauge and alloy of nickel-chromium wire.

New grid wire kit: I keep a bulk supply of this wire on hand, US-made, top quality. I'll promptly send you 20 feet of the correct wire by first class mail for $20. Ships to USA addresses only. (Canada and international addresses: please order here.) Orders are processed same- or next-day from receipt. This is the same grid wire used on all makes and models from the 1970s to the present, and substitutes for the wire in Whirlpool rebuild kits 370853, 4387020, and 2185611; and the GE Monogram kits WR29X10075, WR02X12734, and WR02X12735; competitive prices on these kits are upwards of $80.

You can also order a bulk supply of 100 feet, which is sufficient for five repairs, for $80.

Newer-type grid connector kit: At left is the connector used on the newer type grids. These connectors rarely fail, but when they do they are almost impossible to find. The nylon shell at left is used on the grid itself, and on the right is the shell used on the machine chassis. The grid uses the plug shell with the receptacle pins, and the chassis uses the receptacle shell with the plug pins. One of the crimp pins for each shell are also shown. I stock these items as a complete replacement kit consisting of one of each shell and two of each crimp pin. With this kit you can replace the grid connector, the mating connector on the machine, or both. Order here.

Older-type grid connector: You can also use this newer-type connector kit to replace both sides of the older black-rubber 2-prong grid connector, since the older connector is no longer available. This connector is what we use to refurbish older grids with a failed old connector.

Detailed how-to: See my replacement instructions for the ice machine grid connectors.

My cutter grid has two levels, one that cuts "north-south" and a second that cuts "east-west"; each of these is about 8 feet of wire creating a 10 ohm resistance. These two are wired in parallel to create about a 5 ohm resistance. You can check the resistance with an accurate volt-ohmmeter, and measure the wire diameter with a micrometer or calipers, to make sure you have a similar design. Email from readers of this page confirms that this grid design and wire type is the same across all makes and models. There are two possibilities for the spacing of the grid wires, which correspond to "cubelet" (3/4 inch square cubes) versus "cube" (1-1/4 inch square cubes) size ice, although I've never, ever seen anything but the 3/4 inch version. On some models, the low-voltage transformer that powers the cutter grid also powers a bin light. On recent designs, the transformer also supplies the low-voltage power to the electronic control board.

Grid variations: There are three grid designs I know about:

Despite the difference in design, these all use the same type and length of wire, and they all cut an 8 by 8 inch slab of ice.

Removing the old, broken wire: To restring the wire, begin by removing the cutter grid assembly from the ice machine by removing the two thumbscrews that hold the grid inside the bin, and disconnecting the two-prong low-voltage power connector. You can test the machine by keeping it running with the grid removed. Without the grid the machine should make ice in slabs that drop into the bin and break. You can let the gridless machine run while you complete the grid repair. Remove the plastic bezel from the grid by sliding it off while prying the notches up that hold it in place. The resistance wire is strung in two directions, each a separate electrical circuit; these two are wired in parallel by ordinary insulated tinned-copper wires to the 2-prong connector. Likely only the upper level of the grid wire is broken, and you can restrict your repair to that one circuit, since the upper wire breaks from the repeated impact of the ice slab coming off the evaporator; the lower level very rarely breaks since it does not receive any such impacts. The ends of the wire are clamped in place on top of eyelet connectors by stainless screws. These screws have a Torx T-20 head, so you'll need a Torx driver to loosen and tighten them, (although if desperate you could grasp the screw heads with pliers). Loosening these screws just a bit frees the wire ends. Unthread the old, broken wire from the back-and-forth pattern through the plastic insulators at the edges. The insulators are captured on the metal frame only by the wire tension, so the insulators will come loose from the metal frame when the wire is loose; remember the orientation of the insulators for reassembly. This is a good time to clean the grid with acid cleaner if it has lime encrustation or other debris.

Installing the new wire: Putting the new wire in is a bit of a manipulation, but not too difficult with proper technique. You must first mount the grid frame in a secure work holder, such as a bench vise, so you have your hands free. A serpentine wire threads through black plastic endpieces (I've heard sometimes this plastic is white, and on the later models it is clear). Measure the length (before it was broken) of the removed wire; mine was 8 feet 3 inches. Unspool a slightly longer piece of new wire (I use 9 feet). If you bought your new wire from me, then you should have 20 feet which you can cut in half. Fold this 9 or 10 feet of wire in half to find the approximate center (but don't actually sharply bend the center). Thread the ends through the middle hump of the insulator which is opposite the insulator that holds the connector screws. Thread these two loose ends respectively through the rest of the serpentine pattern, until you reach the end by the connector screws (not unlike lacing a shoe in an uncrossed pattern). You should have at least several inches of extra wire past the connecting screws; if not, shift the wire to even the ends. Pull one loose end of the wire as taut as you conveniently can, wrap it clockwise around the connector screw with the eyelet connector above it, and tighten down the screw. Using your fingers, starting at the same screwed-down end, stretch the wire taut across the grid opening in one direction, and again reversing to the next direction, hand-over-hand, until you reach the other end, and have taken up all the slack you can. It is not necessary at this stage to have the wire very tight; just enough to keep the wire from sagging and to straighten any kinks is enough. Use your fingers for this; do not use pliers or other tools which might nick or otherwise damage the wire as you manipulate. Now here is the secret technique to getting a tight wire all across the grid: wrap the loose end around its still-loose connection screw one-quarter turn, and maintain constant tension on the loose end while you repeatedly "pluck" the spans of wire from the far end back to the loose (tensioned) end. By "plucking" I mean that you pull on the second span from the fastened end to tighten the first span, then take up the slack of the second span by pulling on the third, then the third from the fourth, and so on, until the slack is pulled out of the grid on the the loose end by the constant tension. This constant tension could also be provided by another person helping you with a pair of Vise-grip pliers on the end of the wire, or a weight of a few pounds likewise attached, but you must have both your hands free to "pluck". Repeat the "plucking" a few times until the strings are "moderately" tight, "moderate" as in playing a low note when you pluck them like a guitar string, not so tight as to bend the grid frame. After this step you can "strum" the from the fastened end to the loose end to tighten the segments further. Again, the goal is only to have the wire tight enough to not sag. Once you have pulled all the slack out and strummed the wire segments all tight, fasten the loose end by tightening the second connector screw like the first, all the while maintaining the tension until the screw is set.

Testing and reinstalling the rewired grid: Reassemble the plastic bezel to the unit, and test the grid by connecting it to the ice machine before you install it in place. To test, place the palm of your dry hand against the grid wires when the ice machine is running and the grid is connected; the wires should feel slightly but distinctly warm when no ice slab is on the grid. Once tested, you can reinstall the grid into the machine. At the next harvest, observe that the grid takes about 10 minutes to cut a slab of ice into cubes.

Send your grid in for repair: If you want me to restring your cutter grid for you, you can ship me your broken unit and include a check for $105, or order online. See the packing instructions, shipping address, and online ordering here, or use the buttons at the right. Return shipping is included; USA addresses only. Turnaround on this repair is 1 week after we receive your broken unit. Remember that you can still make uncut ice slabs while you're awaiting the repair; see ''cutter grid is actually optional'' below.

Complete grid assembly: If you want to buy a complete cutter grid assembly, check my ordering page for availability and price of units I have refurbished. You can also order a grid with the plastic panel at additional cost (normally you'll just switch the old panel onto the new grid, but sometimes the grid and panel have gone missing).

Wire kit for old spring-clip type cutter grid variation: An older design for the cutter grid differs from the more recent design described above. The older style uses short segments of resistance wire held in place (and electrically connected) by individual stainless spring clips and posts. Each segment consists of a short length of wire terminating in eyelet loops of about 3/32 inch diameter, the length being 9 inches from eyelet center to center. The wire is a bit thinner, about 23.5 gage (0.022") and 1.5 ohms/foot, although you can get by with my standard 22 gage wire for repairing just one or two segments. This is a more difficult item to repair when a wire breaks, because the spring clips make assembly a four-handed job requiring special tools. The wire segments require a custom winding jig to make them from stock resistance wire. I offer a kit of 3 of these segments for $20 if you want to attempt the reassembly yourself (formerly known as Whirlpool part number 588109). You can also use the button in the previous paragraph to ship me your broken spring-clip cutter grid for repair.

Upgrading an old spring-clip type grid to a newer plastic-spacer type grid: Another possibility for the spring-clip grid repair is to upgrade it to the plastic spacers and use the easier-to-install 20-foot wire kit above. The stainless steel frame on the grid is the same for both types, so you simply remove all the spring-clip parts and rewire with the plastic spacers. These plastic spacers are Whirpool part numbers 2174724 (front), 2174725 (rear), 2174726 (right side, as you face the unit), and 2174727 (left side). You'll need all four of these spacers (I regret I do not sell these parts) plus the wire to perform the upgrade. Regretably, as of 2012, these spacers for the older grids were nowhere available as new spare parts any more.

Transformer for Cutter Grid: The original transformer part for the older electromechanical machines is no longer made and doesn't seem to be available from Whirlpool. A $20 stock unit made by Hammond, their part number 166L8 (8.5 VAC center tapped, 2 amps), which is sold by digikey.com as part number HM510-ND, is a suitable substitution. You can order the HM510-ND online from digikey.com for about $20 plus $10 shipping. You'll also need two each of 3/16-inch and 1/4-inch male disconnects (digikey.com 94807-01 and 94811-01 respectively) to fit the original connectors on the machine, or you can just splice in directly. The 1/4-inch size disconnect is a widely used standard, but the 3/16-inch size disconnect is hard to find in hardware stores.

Grid lifetime: How long should a grid last? Not as long as you might think. These things break because a heavy slab of ice drops on to the top grid layer every time the unit goes through a harvest cycle. Over the years, my grid seems to have lasted a typical 50,000 cycles before it breaks. Considering that a unit could run 50 cycles per day, that could be less than 3 years. (But that's also 25 tons of ice, roughly a semi truckload.) Your grid will of course last longer if your machine runs only intermittently, but while the machine itself may last for decades, the grid won't without an occasional minor restringing repair.


Repairing the Harvest Thermostat Solder Attachment

The older design of this machine used electromechanical controls, including a harvest thermostat on the evaporator plate that clicks on and off with the ice slab temperature. If your machine uses the newer electronic controls, you will have an electronic thermistor on the evaporator instead of electromechanical thermostat, and this section does not apply.

The evaporator plate in the top area of the ice machine circulates the hermetically sealed refrigerant (R-134a lately, or R-12 in very old machines), which boils off to carry away heat from the waterfall passing over the plate, resulting in a layer of ice being progressively built up. The top of the evaporator plate, where the ice forms, is smooth. The bottom is a complex affair containing the refrigerant line connections, and a bracket and clamp holding a capillary tube from the harvest thermostat. A complete assembly (327505 evaporator $266.02) is the only replacement part available from Whirlpool, but the old part can likely be repaired.

To diagnose the problem, it helps to understand the principles on which the machine makes ice. The running machine is always in one of two modes, either ice-making (chilling the plate) or harvesting (warming the plate). The capillary tube senses the temperature of the evaporator plate, which triggers two control events in the machine, depending on what the state of the machine is, and on the temperature reaching a level well-below or well-above freezing:

The bracket and clamp holding the capillary tube are about 1" wide by 4" long. The bracket itself is soldered to the bottom front of the evaporator plate, and a smaller clamping plate is held by a screw post and nut to the bracket. This creates a solid thermal connection between the capillary tube and the bottom of the evaporator plate; inside the tube, a liquid expands and contracts with the sensed temperature. The tube transmits this expansion/contraction pressure to the thickness control thermostat at the front panel, where the pressure triggers the switch that controls the cut-out and cut-in of chilling versus harvesting.

A few inches of the capillary tube should also be soldered to the bottom front lip of the evaporator plate. This helps it to quickly sense the rising temperature during the harvest cycle, which should end as soon as the ice slides off.

The failure of the bracket solder joint occurs because of the repeated cycling of sub-freezing chilling to make ice versus above-freezing thawing to harvest the ice. The area is always wet, and the solder joint will typically have small pockets or bubbles, which when wet will freeze and become slightly larger due to the expansion of the ice. Each freeze-thaw cycle enlarges the flaw slightly, and eventually this grows into a large fracture, just like fracturing of mountain stone from years of winter/summer cycles.

If you suspect you have the problem of the fractured solder joint, you can inspect the joint by removing the cutter grid and reservoir bucket. You can recognize the bracket, since it is the only item in the vicinity having a screw post and nut. If the solder joint does not appear intact along the entire length, but appears cracked or slightly separated, then you have this problem, but perhaps not very badly (yet). If the joint is mostly cracked, such that you can wiggle the bracket; or if the bracket is completely loose from the plate and is being held only by the capillary tube, then you have a definite problem needing repair.

The bracket is hard to view directly without pulling out the evaporator plate, which is a big job. You should be able to blindly feel around to the front or back of the bracket, nudge it with your fingers, and find it moving relative to the evaporator plate. Indeed, if the solder joints have almost completely failed, the bracket can fall right off with this manipulation.

While I used to recommend a difficult repair of resoldering the bracket, you may want to consider the re-location bracket kit that Whirlpool introduced in 2006 to deal with this problem.

The repair to resolder this bracket is a bit challenging. You must first remove the cutter grid (remove two thumbscrews), reservoir bucket (remove two thumbscrews), and recirculation pump (remove three acorn nuts at rear wall, disconnect recirculation tube from top of evaporator plate). Your design may vary slightly, but so far these steps should not be too difficult.

The first difficult step is next, to get the evaporator plate out of the interior of the bin while it is still connected to the refrigeration system. Remove the two thumbscrews that hold the plate in place. Observe that the plate is free of fasteners but held in place by 1/4" refrigerant tubes and 1/16" capillary tubes, made of copper, perhaps tinned, somewhat flexible. You must now manipulate the plate out of the bin, bending the refrigerant tubes to allow the plate to swing out through the door, such that it presents the bottom of the plate in the upwards direction. While the copper tubes cannot take a lot of this kind of bending, and you should be careful not to kink them, they can take a few rounds of this type of manipulation before they work-harden enough to crack.

If you should crack the refrigerant line tubing, you will hear a hissing sound from the pressurized refrigerant gas escaping, possibly with some entrained oil. If the refrigerant escapes as a cold liquid spray, stay clear of it (evaporating R-134a can cause frostbite in contact with skin). If the leak is not too close to the plastic bin, it might be possible to repair it with a soldered patch or repair fitting, but that will require an evacuation and recharge of the refrigeration system which is beyond the scope of this document. Otherwise you will need a replacement for the evaporator plate unit which may cost more than the value of the repaired system.

Assuming you have the bottom of the plate facing up, and clear of the bin, and haven't cracked a tube, you can better inspect the condition of the thermostat capillary tube bracket and the solder joint. If it indeed shows fatigue or failure, you should repair the joint. Good soldering practice is essential here. Clean the area as best you can first with a wire brush, and apply a generous amount of non-acid flux. Heat it up quickly (a pencil torch is marginally effective; I use a Turbo-Torch to get a lot of heat), and feed and wipe with lead-free solder. Apply and withdraw the flame in cycles to keep the area just above the solder free-flow temperature, and keep the overall time to the minimum needed to get a good joint. Don't worry about solder splashes or blobs falling across the plate; they'll clean up eventually even if they wind up in the reservoir later.

Soldering or brazing on a charged refrigerant system is normally not feasible. The liquid refrigerant and oil should have collected in the bottom of the unit and not up in the evaporator plate, so that the soldering of the adjacent surface to the refrigerant circuit does not require evacuation of the unit. You are not loosening a soldered joint or fitting under pressure, just the mechanical attachment of a bracket. If you can get it done quickly and at a low temperature, you can expect that the heat damage to the residual oil or refrigerant in the area will not be enough to impair the function of the refrigeration unit. The ideal technique would be to add a repair fitting to the process tube on the compressor, evacuate the refrigerant, flush the oil, charge with inert gas, solder, evacuate, and recharge the refrigerant system, but this may not be practical.

Once you have a good solder repair, and the part has cooled, you can reverse the disassembly, starting with manipulating the evaporator plate back in to position at the top rear of the bin. Replace the circulation pump and hose, the reservoir bucket, and the cutter grid. Before replacing the bucket and grid, you may want to start the unit and feel the evaporator plate with your hand to see if you still have refrigeration operational.

A new solder joint should last some years at least. Recurrence of this problem does seem inevitable, because of the nature of the freeze-thaw cycling and how it repeatedly applies destructive force at any wet gap or void in the joint.

You will find stray bits of solder and related debris in the reservoir or ice bin after performing this repair and running the unit. Of course you will have used lead-free solder, so this is not a concern.

You may be told by a repair service that this is a brazed joint that is impossible to repair. Refrigeration technicians like to braze joints because this is much stronger than soldering, and part of their technical training and equippage. After inspecting 8 of these units, and repairing one, it is clear that this joint is made at the factory with ordinary low-temperature soft solder that is quite feasible to fully repair. The hard part is getting the assembly out of the ice bin without cracking the connected tubing.

Someone emailed me to report that he had repaired the bracket attachment with epoxy cement instead of soldering, which can be done inside the bin without the difficulty of extracting the evaporator assembly. While the thermal junction cannot be quite as good through epoxy versus solder, it apparently is enough to work, perhaps with a bit of temperature offset to the thickness control. Stainless steel bonds well with epoxy, but make sure the metal is cleaned, warm and dry before trying this.


Adjusting the Harvest Thermostat

If your ice thickness control doesn't respond properly, but your sensing bracket seems to be properly in place, it is possible the thickness control thermostat itself has simply drifted out of calibration and just needs an adjustment. This is an easy repair, assuming you ruled out the loose bracket first. Remove the escutcheon plate from the front, exposing some tiny adjustment screws on the thickness control for the cut-in and cut-out temperature setpoints. You can twiddle those adjustments. The cut-out screw sets the colder temp for the harvest trigger, the cut-in screw sets the warmer temp to end the harvest. Set the control (knob) to the middle of the thickness range, and wait for the ice to build to a medium thickness, and then adjust the cut-out screw until it triggers the harvest. These screws have a range of several turns of adjustment, so you may have to turn them 1/2 or a full turn before you see any difference in performance. When making these adjustments, count the turns you apply to either screw, making notes of that, so you can return the control to its prior settings if you get lost.

Even if the bigger problem is the loose evaporator bracket, you can compensate to an extent by adjusting to cut-out setpoint on the thickness control to a warmer temperature. But you won't have fixed the problem in the long run, and the thickness control will be poorly responsive since the thermostat doesn't have a solid thermal contact with the evaporator plate. Poor response can result in harvest intervals that start too soon, too early, or inconsistently; and also in harvest times that are too short or too long.

If you want to adjust the harvest thermostat to shorten the harvest time, remember that the harvest time is deliberately longer than the time needed to just refill the reservoir. The reservoir is flushed with an excess of refill water, which then overflows into the drain tube, so that the high mineral content of the old water is replaced with new water.


Repairing the Solenoid Valve

As described above, the solenoid valve that controls incoming water flow can fail in an open or closed manner. This is Whirlpool part number 386433 on my unit. This valve is located at the bottom right front of the unit, just inside the kick panel, where the water connection is made. These valves are a common replacement item, and in fact easy to remove and replace if you just want to pony up for a new one. This same valve is apparently used on a lot of appliances, as I have seen it on washing machines and dishwashers, so if you don't want to fuss with the rebuild, you can take it to an appliance parts counter and expect to find it for, oh, $40.00, which is most likely about $39.99 more than it will cost to fix it yourself. (I'll admit than now when I see someone discarding a dishwasher or refrigerator on the curb on trash night, I'm tempted to stop and look for a solenoid valve to scrounge!)

The 1-cent failure is nothing more than the inevitable deterioration of a tiny rubber gasket which is trivial to repair. You might fix this faster than you could even find a replacement.

To remove and repair the valve, first remove power (120 VAC power runs this solenoid). Shut off the water supply, and disconnect the water inlet and outlet connections to the solenoid valve. Remove the electrical connector. Remove the mounting bracket screw(s), freeing the valve. Remove the screws to disassemble the valve unit, observing the solenoid plunger with a recess tip containing a tiny rubber gasket plug (or remnants thereof). This rubber item is originally a disc about 1/8" diameter and 1/16" thick, stuffed into a recess of the same size on the tip of the plunger cylinder. The rubber may be partly disintegrated or missing altogether.

You can cut your own replacement rubber piece quite easily. I made mine using a leather punch on a 1/16" thick sheet of rubber gasket material. The usual Buna-N (nitrile rubber) material is fine, such as is available from plumbing suppliers, auto parts stores, or online at Enco (such as p/n 240-2326). You could also take a common faucet washer, and carve it with a razor-sharp hobby knife to proper thickness and diameter. The exact disk shape is not critical; what is critical is that the outside face is flat and smooth, which you can ensure by just using an original flat surface of the faucet washer on that side. Reassemble, reinstall, enjoy the satisfaction of a cleverly improvised, do-it-yourself success.

Some of the service manuals refer to 0.31 gallons per minute flow from the solenoid valve. This would be a good target flow to measure when testing the function of the valve with the plumbing disassembled and the water running into a bucket. Run the valve open for a timed minute while catching the water in a bucket, and measure the water volume caught. It should be 0.31 gallons (40 ounces) or more.

Testing for a stuck-closed solenoid valve: Testing the solenoid valve for being stuck-closed is not difficult. Understand first that this valve only opens during the harvest portion of the cycle, when the fan has stopped and the refrigeration unit is reversed and hissing slightly. If the machine has been turned off and sitting idle for a while, turning it on should not activate the water valve solenoid, it should simply start chilling, and if there is water in the reservoir, it will proceed to make a slab of ice; if the reservoir is empty, the evaporator plate will chill down rapidly, and in a few minutes the harvest cycle will trigger, only then should the water solenoid valve open. If you've removed the reservoir bucket, then you should be able to see the stream of water entering the unit, and even catch it in a bowl to measure the volume.

The hot gas solenoid and water valve solenoid are in parallel, so if the unit reverses during the harvest and rapidly warms the evaporator plate, then the controls are OK. The switching of the solenoid valves is performed by the thickness control thermostat behind the escutcheon plate.

Testing for a stuck-open solenoid valve: To test if the solenoid valve is stuck open, even just a trickle, you can remove the reservoir bucket and see if water runs from the supply tube during the chilling part of the cycle. If you suspect a trickling valve is spoiling performance, you can shut off or disconnect your water supply completely (make sure you have a solid shutoff valve, not even allowing a trickle) at the end of the harvest, and see if the performance problem goes away for the rest of that cycle.

Testing for restricted water flow: To measure how much make-up water your machine is admitting each cycle, remove the reservoir bin and catch the water flowing in during the harvest. This volume should be at least several changes of the reservoir volume of about 1/2 gallon (the slab itself will have consumed about 18 ounces of water), so you should catch about a gallon or more during a 1- or 2-minute harvest. If the supply pressure is OK, but the machine admits less water, then you must have some kind of restriction or too-short harvest time.

One can also benchtop-test the solenoid valve for stuck-open, stuck-closed, or restrictions, by removing it entirely and activating it manually. The water inlet connects to an ordinary garden hose. For the electrical test, I assembled a "cheater" AC plug and cord with 1-amp inline fuse and female spade lugs, and connected this to the solenoid's terminals to apply 120 VAC. Apply the inlet water pressure, and (keeping yourself dry) briefly insert the AC plug into an outlet.


Recharging the Refrigeration Unit

This section is for technicians and advanced do-it-yourselfers who have the tools and knowledge to charge A/C and refrigeration systems. If you're not a do-it-yourselfer and wanting advice about hiring a technician offering an expensive repair, see my tips under diagnosing poor performance below.

The performance specifications on the "Service and Wiring Sheet" indicate that the machine should harvest a medium-thick (about 0.45") slab of ice every 18 to 22 minutes under favorable conditions (ambient temperature 70 deg F and incoming water temp 60 deg F). This production rate will slow to 30 to 38 minutes under unfavorable conditions (ambient temperature 100 deg F and incoming water temp 80 deg F). If the production is slower, then the cause may be an undercharged refrigeration system.

The refrigeration performance of the ice machine design is very sensitive to undercharging, because (1) the refrigerant charge is so small to start with, only a few ounces, hence a tiny leak can turn into a problem quickly, and (2) expansion is controlled by a capillary-tube (no feedback, "open loop" control) instead of an expansion valve (closed-loop feedback control). While this open-loop sensitivity is a disadvantage in that any leak will degrade performance, it also makes the diagnosis of a low-refrigerant condition easier because the degradation is easy to observe and detect.

Another symptom of low charge is that the slabs of ice are distinctly thinner in the middle (not just wavy). The refrigerant circulates through the evaporator plate in a rectangular spiral from the outside edge to the center. If the refrigerant is slightly low, it boils off and chills the edges well, but by the time it reaches around to the center, it is all evaporated, and there is no phase change remaining available in the refrigerant flow to chill the center area. See my tips under diagnosing poor performance below.

Recharging the system first requires that you add an access fitting, because the system as shipped from the factory is a sealed unit. A 1/4" OD copper process tube exits the front of the compressor, which at the factory was used to charge the system, pinched off, and brazed shut. This is the suction side of the compressor. This process tube is intended to be fitted with an access fitting should recharging ever be needed. I used a 1/4" flare male Schrader valve fitting, which happens to fit my refrigeration gauges. An automotive low-side fitting is more appropriate.

While soldering or brazing a fitting on the process tube is the most reliable way to proceed, installing a clamp-on line-piercing valve [grainger.com example] is feasible and much easier. This has the advantage of requiring no soldering or brazing, instead using mechanically compressed elastomeric seals, but will eventually leak when the seals get old. This line-piercing valve will provide a 1/4" flare fitting, to which you can add an adapter for 1/4" flare to R-134a low-side quick-connect fitting. This adapter is available for a few dollars in the auto parts at Walmart (sold for retrofitting R-12 auto air conditioners). Then you can use normal R-134a recharging cans and gages from Walmart to add refrigerant, although you must take care not to overcharge since the system contains less than 1 lb of refrigerant total.

To add this fitting, I followed these steps:

Another method simply has you solder or braze the fitting onto the end of the pinched tube, and then open up the pinch a bit with pliers, or drill a small hole. This is not as good a connection for running a vacuum, but it retains the existing charge, is easier, and is sufficient for metering and charging the system.

After the access fitting is installed, you can attach refrigeration gauges, evacuate the system with a vacuum pump, and recharge the R-134a refrigerant by weight. The weight of charge required is specified on the serial number plate on the edge revealed by opening the ice bin door; my system specifies 6.75 oz. Weighing the charge in is required to get this amount correct within an ounce or two more and none less. Charging by observing performance is possible, but takes a long time, since you must start with a minimal charge and observe a number of harvest cycles while adding small amounts. Undercharging will result in the ice slabs being thin in the middle. Overcharging will result in the suction tube frosting towards the end of the cycle, just before the harvest, where the tube exits the bin into the lower compartment (the excess cold liquid refrigerant does not vaporize in the evaporator, and trickles down into the tube). The timing of events in the cycle in minutes, beginning at the harvest trigger, is thus:

PRODUCTION CYCLE OF THE ICE MACHINE
Elapsed Time (mm:ss)
(under typical conditions)
Events
0:00 Start of harvest: Evaporator thermostat senses its below-freezing cut-out setpoint, and triggers the hot-gas recirculation solenoid to begin harvest. Hot-gas recirculation heats the evaporator, thawing the bottom of the ice slab that has up to now been solidly frozen. Water solenoid energizes, sending fresh, room-temperature tap water into reservoir, with excess overflowing into drain tube which directs the overflow down the drain without rinsing and melting the existing ice in the bin. Suction-side pressure quickly rises from terminal 1 to 6 psig, up to 60 to 100 psig, due to the reversal.
1:00 Mid-harvest: Continued thawing loosens ice slab from evaporator plate, and the slab slides off onto the cutter grid. The slab makes a "thunk" sound when it hits the grid assembly and comes to rest on the top grid wires. The evaporator no longer has ice on it, so its temperature now rises above freezing due to the hot gas flowing through it from the reversed refrigeration unit.
2:00 End of harvest, start of liquid water chilling: Evaporator thermostat senses its above-freezing cut-in setpoint, de-energizes hot-gas solenoid to restore chilling. Water in reservoir is above freezing (now a mix of previous chilled water and fresh room-temperature water, proportion depending on how long the harvest took), but begins to chill as it recirculates over the evaporator plate. Suction-side pressure quickly falls to 10 to 15 psig range, and continues to fall as water chills.
7:00 Start of ice formation: Water fully chilled to freezing point, and ice begins to form on edges of evaporator plate. Suction-side pressure in the refrigeration unit declines to 6 to 10 psig.
10:00 Ice builds in thickness: Evaporator plate now fully covered with a thin layer of ice. Bottom of evaporator plate is well below freezing, but not enough to trigger the harvest thermostat. Suction-side pressure at about 6 psig.
18:00 to 22:00 Triggering of harvest: Ice has formed a full-thickness slab on evaporator plate. Top of slab is covered with recirculating water and is at freezing temp. Bottom of slab and underside of evaporator (with capillary sensing tube to thermostat) are well below freezing. As the ice grows thicker, the heat transfer slows, and the evaporator temperature progessively falls, eventually triggering the thermostat setpoint, and the cycle repeats. Suction-side pressure declines to minimum of 1 to 6 psig, depending on ambient conditions. Note: it's not unusual for thicker cubes or older machines to take about 30 minutes to cycle; but anything much longer than that is poor performance, indicating the need for repairs.

For electromechanically controlled machines, the above timings are approximate, the actual harvest time depending on the return of the harvest thermostat to a warm temperature. On the more recent electronically controlled machines, the hot-gas harvest portion of the cycle lasts exactly two minutes during which the reversing valve is always energized, but the water valve is opened only for the first minute of the two minutes to rinse and refill the reservoir. Electronic machines, when first turned on, also run an initial three-stage flush for five minutes, consisting of two minutes of water intake with no circulation, one minute of circulation with no water intake, and two more minutes of water intake with no circulation.

Since a harvested slab is finished being cut into cubes some time before the following slab is harvested, it can take two full cycles, or about an hour, before the first cubes have dropped into the bin after an initial power-up.


A Few More Tips on This Machine


"Bene diagnoscitur, bene curatur."
  —Latin proverb
Translation: Good diagnosis, good repair.

Have a comment or question about my ice machine repairs?
Need to thank me for saving your expensive ice machine from the junk pile?

Email me at:
kinch@truetex.com
Richard J. Kinch
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