White-Westinghouse side by side fridge MRS24WRED1

[paparentman]

Our refrigerator is clogging up with frost. From this site I've determined that it is not automatically defrosting, and problem may be with timer, heater.

I've done some looking, but I haven't found where these parts are living so I can test them.

 

Advice appreciated.

[Samurai Appliance Repair Man]

Bottom LHS in front, right behind the toe grill, you'll find the defrost timer (item 23). Turn it 'till you hear the big click and then listen for sizzling and hissing in the freezer. May need to disassemble slightly to facilitate listening/observing. Give it a few minutes. If nothing, then probably a bad defrost thermostat. If it starts hissing and spitting after a while, probably a bad defrost timer.

[stumpowitz]

As per our esteemed  leader, Advance the timer and if no luck with listening for the sizzle, get yourself a decent VOHM meter and post back. We will help you to decipher the intricate workings of the mysterious inner workings of said machine.

[paparentman]

Moving timer doesn't get any responce from freezer compartment. Timer appears to be working ok. Refrigerator goes off with the larger click, and turns on sometime later.

Thermostat and heater next? Where to find those?

[AccApp]

They are buried in the ice. Easest way to get to them for a novice would be to shut it off for at least a day with the doors open and let all the ice melt. Then you will be able to see the screws which hold on the back panel in the freezer compartment which covers the evap coil. Once in there you can check the heater for continuity as well as obvious breakage. If it is good, the def limiter or defrost thermostat is faulty. Don't test it at room temp as it should close at below freezing temps and open near the temp marked on the side.

[paparentman]

I have defrosted the freezer about 4 times now. I take off the back panel and put a small heater inside, setting on a bucket so it blows right on the ice. Melts in about 30 minutes. Even with everything melted I haven't been able to pick out the heaters.

Are they tubes with wires running to them? Verticle, horizontal?

Thanks

[Pegi]

Defrost heater is ref. # 14 in this breakdown, wraps around the evaperator coil...check it with your ohm meter to see if it is broken or not...

[paparentman]

Thanks for the diagram.  

Heater appears to be ok. Very little resistance found.

Is the thermostat #21 on the diagram?  I see it is attached to the heater wire.

Visual inspection of thermostat shows deformity of the top where it has bend upwards off the main case.

Don't quite understand testing of thermostat.

Thanks

[Pegi]

21 is the defrost termination thermostat, will show cont. when cold but will show open when warm...if deformed I might suspect that could be bad, not giving voltage to the heater when the timer takes the frig into defrost...

[paparentman]

I replace the thermostat and then clicked the the timer over to activate. Never noticed any hissing or spitting but the freezer continued to work properly.

 

Thanks for the help.

[Poobah]

The def. thermostat you replaced must be cold before it will close.  As ythis piece is what controls the heater opens to turn heater off at about 50-55 degrees, closes to be ready to initiate defrost at about 20-25.  After letting it get cold then advance your timer