Our refrigerator is not working. We have had the repairman come out 3 times and he has replaced the defrost heating element, the fan, and the defrost timer. Does anyone have any familiarity with this issue to offer a solution. It is a Kitchenaid Superba 42.

I believe your problem is the defroster circuit . There are only three components on most refrigerators unless you have something real special . Kidding . They are as follows : defrost timer , heating element , and defrost cut out switch . The defrost timer cycles the refrigerator out of normal operation and into defrost mode once every six to eight hours depending on the unit . When in this mode everything shuts off , compressor , circulation fan , and condenser fan is so equipped . To eliminate the circulation fan , you'll have to keep an eye on your refrigerator checking in every half hour or so for six hours to eight hours and see if it stops working . If it does , then we know the timer is working correctly and the problem will be the heating element or cutout switch . The heating element is checked with an ohm meter. Usually they burn out when they go bad and you will read infinite resistance. The defrost cutout switch should read 0-1 ohms when the freezer temperature is 40° F or lower. If the heating element checks good , in other words it shows to have resistance usually between 30 and 100 ohms, replace the cutout switch . If the circulation fan never shuts off and the unit continues to run without shutting down after a six or eight hour Time cycle , replace the defrost timer . Good luck

Most likely the defrosting heating element has burnt out and needs to be replaced. I know it seems contradictory but modern refrigerators rely on a heating element cycling on a couple of times daily to keep the condenser core from freezing up.

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A refrigerator must defrost 2 - 3 times a day. It does this via the automatic defrost cycle. When the cycle starts alll motors shut off and there is a heating element that is in the evaporator / freezer section of your unit. That heating element melts the ice until the 60 Deg F bi-metal thermostat cycles and terminated the automatic defrost cycle. During the defrost cycle is is normal to hear a hissing sound as the melting ice drips on the heating element assy. Addiionally you may hear coolant gurgles as the unit shuts off to start the defrost cycle and the coolant system equalizes the internal pressures between the pressure and return lines. Again another normal sound. If your unit did not stop to defrost 2 - 3 times a day in a matter of 3 to 4 days you would have a large block of ice in the back of your freezer section and the evaporator fan blades would be hitting that ice block. The freezer would say cool yet probably no longer make ice. Also the fresh food compartment would start warming up. Hopefully this resolves your concerns. If you need more assistance just respond to this post and I will help you.

Thanks for choosing FixYa.

Kelly

Hi and welcome to FixYa. I am Kelly

I am going to paste part of your text and then reply:

Your text:

Repairman came back and replaced a small round part at the top of the evaporator (resistor??) <
{ That was the termostat}

I just read that the problem could be the defrost thermostat..

He already replaced it.

I hate to say it but is sounds like your in repairman hades.

So far I see 1. a new mother board, 2. new defrost thermostat and 3. new defrost heater element. (other than wiring that is everything in the circuit)

Either one of the 3 NEW parts is bad or...there is a partially broken wire in the circuit.

Hopefully this helps you understand. ( I know it does not fix your uint)

Thanks for using FixYa.

Kelly

P.s your words again:

one would expect this to be remedied.
You got that right!

the timer is the control on defrost time and it is the one that when you hear the compressor fan stop working and the fan in the feezer stop working too ...the unit get into defrost time... see if your timer need to be change...good luck

With the defrost timer being replaced already it sounds as if the repairman is not looking at the real problem. Unit works for 2 days then things start thawing. Hint Hint... it is not defrosting. There is a heating element inside the freezer section attached underneath the internal tubing that melts the ice every 6 to 8 hours via the defrost timer depending on the defrost timer installed. To prove that it is not defrosting..... just unplug the unit and place a stand fan blowing into the freezer for about 90 minutes. I would bet that once you plug it back in it wil work for 2 days and the problem once again repeats. With 2 calls on the same unit and you still have the same problem I would be calling the service people back and demand they fully troubleshoot the defrosting element and thermostat. Personally this is an unstatisfactory performance of an in home service by a repairman. With the exception of a new part if required, they should wave any labor and service call fees.

If freezer is icing up, you might have a defrost problem. Frost free models have a heating element that is controlled by a timer to automatically defrost ice, ie defrost timer turns on defrost heating element every 12 hours to melt ice in freezer and allow good air flow.
You can test defrost element with an ohm meter(located inside freezer coils-will have two wires going to a plug connection), if OK replace defrost timer (located in various places depending on make and model

yes it could. you again have a defrosting problem. do you noticed frost at the back side of the freezer section? the repairman could have replaced your heating element and your defost timer.

Sounds like you have a defrost problem. The timer could be playing up and taking too long to defrost, which causes the evaporator to ice up, hence no cold air to the fridge and the water line freezes up, hence no water dispensed. When the timer does eventually defrost the fridge then everything returns to normal. This could also be caused by a faulty defrost terminator or bad connection on the defrost element.