Maytag side by side auto defrost problem

[m0t]

We had a lot of lighting strikes and power surges a couple of weeks ago and since then our Maytag side by side has been playing up.

First I discovered that the freezer was not getting cold, but had frost built up all over the back of the unit. I took the back off and discovered the coils were a solid block of ice.

I manually defrosted the coils and advanced the defrost timer to check its operation. The defrost timer did not shut off the condensor and the fridge continued to run in cooling mode.

I bought a replacement timer and plugged it in. I tested its operation by advancing to the next setting, this resulted in the condensor shutting off, however the heating coils did not get hot.

I tested the defrost thermostat which showed a resistance of 0.00 and checked for continuity along the coils. The bottom one was not passing current so I ordered a replacement set.

I installed the replacement set and checked the operation, again the coils did not get hot. I rechecked the timer and thermostat and both showed correct operation. I then checked the new coils and the bottom one was not passing current. I then visually inspected both sets of coils, and both the old and new coil set had broken apart in exactly the same place on the bottom coil.

Is this just bad luck or is there a problem elsewhere (too much current reaching the heaters?). What should I check next?

Many thanks,
Tom

[paul_h]

Is there a thermal fuse, or just the coil klixon (which I think you are referring to by the defrost thermostat).
I don't know the fridge, but from what you're describing it's a simple mechanical timer which also has a klixon (only defrosts if cold enough), the same as smaller samsungs.
Samsung fridges also have a thermal fuse as a safety to cut power in case the timer and klixon fail. Some brands have the klixon and fuse in one package, some have them separate, so it's hard for me to know whether the thermal fuse has been tested.
The heaters normally run on mains voltage, switched by defrost timer, so I can't see them passing too much current unless the fault is in the heaters themselves.
Maybe one heater is shorted, maybe the thermal fuse or klixon is faulty. The klixon should be open circuit above 0 Celcius, if it's showing 0 ohms across when it's not that cold it's faulty

[m0t]

According to the wiring diagram there is no thermal fuse, and to be certain I traced the wires around the fridge and found nothing.

Testing the thermostat results in 0 ohms resistance below 0 and above 0 I read infinity.

[Cuban Misu]

Hi I have a maytag side by side, that the coils in the freezer have frozen into a block, it then froze the fridge so much that it cracked the water filter. I had a repair man come out and he told me for a new thermostat and the service call it would cost just under $500.00. I called the parts sor to order a new thermostat and the gentleman told me there were 2 any idea which one it is?

Thanks

[kiwireeferman]

Hi I have a maytag side by side, that the coils in the freezer have frozen into a block, it then froze the fridge so much that it cracked the water filter. I had a repair man come out and he told me for a new thermostat and the service call it would cost just under $500.00. I called the parts sor to order a new thermostat and the gentleman told me there were 2 any idea which one it is?

Thanks

Was the repairman also wearing a mask and carrying a gun?