[DaveB2742]

My Refrigerator stopped working and found that the cooling coils were covered in Ice. Behind it was the defroster heater coil that was FRIED!(melted)

My question:
There is what appears to be a sensor connected to this coil.
Should I be replacing this too? There is no continuity between the 2 wires of the sensor when disconnected. Ohm resistance "0".

I don't have a manual with the specs.

Thanks in advance

[denman]

Here is the parts breakdown for your unit
Whirlpool KSSS36QDX00

You are probably looking at the defrost thermostat

Your post is a little confusing. You say no continuity and the that it reads 0 ohms
0 ohms is continuity. It is a dead short

The thermostat should read 0 ohms when cold and infinite ohms at room temperature. It shuts power off to the heater when the coils have been defrosted.

[DaveB2742]

denman the part I was talking about is Partselect.com - Whirlpool Refrigerator Parts And All Brands of Appliance Parts
Picture in the Lower unit and control part is labled #1

Where is the defroster control. What section and part?
Thanks for your help. I have to get to work so I don't have time at the moment to look a long time for it. I can't find it labled as a defrost controler.

[DaveB2742]

I finally have some time at work to take a better look through all the parts.

There is also what they call a timer-Def.( PS327819
TIMER-DEF )

I take it, that this determines how long the heater stays on, BUT does it override the thermostat if that's what this part is below :
Partselect.com - Whirlpool Refrigerator Parts And All Brands of Appliance Parts

How do you test the timer?

Thanks

[denman]

Using the link I sent for this unit

The defrost thermostat is Item 1 in the LOWER UNIT AND TUBE section

The defrost timer is Item 30 in the UPPER UNIT section

The way it works is:
The timer usually makes one rotation every 8 hours or so
Once every rotation it closes the defrost contacts for about 30 minutes
This time is fixed
The unit goes into defrost
The circuit is defrost timer contacts, defrost thermostat and the heater
Because icing up varies due to usage the defrost thermostat opens when the ice on the coils has melted.
The timer continues in defrost mode but the heater is turned off due to the thermostat so you are not producing heat in the coil area that is not required to defrost the coils.

Here is a good link with defrost help/troubleshooting
refrigerator problems and solutions, not cold enough, frost free repair information

[DaveB2742]

Denman:
Thanks again for your help. Replaced thermostat and coil. Frig works great. Timer proved to be ok.

I was trying to find what cause the coil to fry. It seems the thermostat (bi-metal sensor) was a good part of the problem. I compared the ohm resistance of the new one to the old. Instead of 1.0 it was .3 when cold. The coil probably needed to be replaced sooner too.

You never can tell until the whole thing shuts down.