The problem started about a month ago. My refrigerator keeps running without "rest". I’ve cleaned the dust from the coil and the frost on the evaporator by turning off the machine for 24 hours.
The refrigerator still keeps running without stop and frost seems to come back gradually. The ice maker functions well.
I am thinking of changing the electronic control (part#2313177) and/or the heater. I did not find the timer or thermostat in the defrosting system for this model. If I fix it myself how can I tell whether or not the control/heater are broken? Would appreciate if anyone can help.
I am not sure why you think it is a defrost problem.
Did you see that the evaporator/freezer coils where iced/frosted over to the point that the evaporator fan cannot pull air through them?
Also if it was a defrost problem after you did the manual defrost the compressor should have come on and stayed on till the freezer reached set point temperature. Then it should have cycled normally until the frost built up to the point where it clogged the evaporator coils. This would probably take a few days. It then would come on and stay on all the time.
It would be a good idea to measure the actual freezer temperature with a thermometer. It should be 0 to 5 degrees F. If lower you may have a temperature control problem.
Is the condenser/compressor fan also running all the time? It should be on whenever the compressor is on.
I am not sure why you think it is a defrost problem.
Did you see that the evaporator/freezer coils where iced/frosted over to the point that the evaporator fan cannot pull air through them?
Also if it was a defrost problem after you did the manual defrost the compressor should have come on and stayed on till the freezer reached set point temperature. Then it should have cycled normally until the frost built up to the point where it clogged the evaporator coils. This would probably take a few days. It then would come on and stay on all the time.
It would be a good idea to measure the actual freezer temperature with a thermometer. It should be 0 to 5 degrees F. If lower you may have a temperature control problem.
Is the condenser/compressor fan also running all the time? It should be on whenever the compressor is on.
— End quote
Hi Denman: Thanks for your prompt response and the attached info. I did manually defrost by turning off the fridge and idled it for 24 hours. Everything seemed working ok for the following several days until recently. The frost is building again and the fridge is running all the time.
If you go to the Sears parts site they have actual part breakdown diagrams that may be useful to you.Unfortunately they do not share these with other sellers.
First remove the evaporator cover in the freezer so you can see the coils.
If they are heavily iced/frosted over then it is a defrost problem.
Do not let them de-ice.
If yes.
Manually force a defrost cycle, see the tech sheet I attached earlier. When the fans and compressor turn off you are in defrost.
Now check the defrost heater to see if it is on.
Be careful you do not want to burn your fingers.
If the heater is on then the control board needs replacing as it is not programming in the defrost cycles.
If not on.
Unplug the unit.
Remove the wire for one side of the heating element from the wiring and measure it for continuity, usually around 20 ohms or so.
If the heater is OK
Remove one wire to the defrost thermostat and measure it, should be 0 ohms when frozen. Note that it opens just above freezing so must be frozen to check it. Also inspect it, if it is bulged at all replace it even if it measures OK.
If both the above are OK then odds are the control board is toast.
Only other thing would be a bad connection from the board to the defrost heater/thermostat combo.
I was trying to force defrost by first holding door light switch closed, pressing refriderator temperature down key pad three times consecutively within 10 seconds and then releasing the light switch. Instead of getting defrost display, I only saw temperature went down 3 degrees.
Thanks for your quick response. I’ve taken a picture of the defrost system as attached for your review. The evaporate was full of frost.
There are wires of red, brown, green , white and black colors. Of what wires exactly should I measure the voltage? I have almost zero knowledge about the fridge:o What is the black unit with red/brown wires and next to the sticker "556"?
There are wires of red, brown, green , white and black colors. Of what wires exactly should I measure the voltage?
What voltage are you referring to?
[COLOR="Blue"]
What is the black unit with red/brown wires and next to the sticker "556"?[/COLOR]
That is the defrost thermostat.
Should be Pink to White according to the wiring diagram.
One side of the defrost thermostat goes to the control board (pink)
The other side of the thermostat goes to one side of the heating element (brown).
The other side of the heating element goes to Neutral (white)
I did not get 120V or so either on heater or on the thermostat. It was a little difficult to measure - I only measured the tiny holes (connectors) in the harness. Then I turned off the fridge and unplugged the connectors for the two wires of the heater. I tested the continuity of the heater. The resistance is about 40 ohms. Do you think the heater is OK despite no voltage shown while the fridge was on.
I would like to focus on the thermostat. All the Youtube I watched showed that the two wires of the unit were cut off before testing for continuity. I was a little hesitated to do so. Is there any way to pull them off directly from the harness?
Heater resistance looks OK
It looks like the defrost has to be cut. See the replacement below, it does not have connectors on it. Be sure to unplug the unit when doing this.
Be sure that it is frozen when checking it as it opens just above freezing.
Some people recommend immersing it in ice water, I am not a fan of this.
I prefer to hold it’s metal face onto a ice cube.
It should be 0 ohms when frozen.
If it is deformed/bulged replace it even if it measures OK.
To install or reinstall the thermostat you can use a couple wire nuts.
Then situate them so the open end faces down so water cannot get into them.
Some folks also like to seal the open end with a sealant as an extra precaution.
You should have seen 120 volts across the heater when you forced a defrost cyle but perhaps did not because tou were not getting a good connection.
Looks like the thermostat has no continuity. I’ve ordered a new part from Appliance Parts Pros.
Do you think a defective defrost thermostat is also a major factor causing compressor and/or fan(s) running constantly? Sometimes the running noise became a little quieter, but never stopped. Sounds like it was the noise of fan(s) only, but I am not sure.
Yes an open defrost thermostat will cause the compressor to run all the time.
The evaporator coils get clogged with ice/frost so that the air cannot be pulled through them and therefore it does not get cold enough. The thermostat then keeps the compressor running trying to get the unit down to set-point temperature.
The noise may be due to the compressor running too long, I cannot say for sure.
I would check to be sure it is the compressor and not the fan.
could be a sign that the fan is on it’s last legs.
The new thermostat came today. I put it in cold water with a lot of ice (as it was a little difficult to hold it closely contacted with an ice cube). On the lowest scale (200 ohm) no reading came up (still "1" or the needle did not move in another meter). Then I changed the scale to 200k, it was shown as 56. Later I measured the resistance at room temperature and I got the same result.
Finally got a good defrost thermostat installed. It seemed defrost system is working - no built-up frost seen. The fridge still keeps running, but the compressor does not seem to running all the time judging by the noise from the fridge. Looks like the condenser fan is running all the time. Is it a problem? If so, how to check and what to do? As always, appreciate your kind help!
The fridge still keeps running, but the compressor does not seem to running all the time judging by the noise from the fridge. Looks like the condenser fan is running all the time. Is it a problem?
It could be a problem.
Depends on how long the unit has been plugged in.
If the condenser/compressor fan is on then the compressor should be on as they are wired in parallel.
You may want to check the compartment temperatures.
The freezer should be 0 to 5 degrees F.
The fresh food should be close to 40 degrees F.
At these temperatures the compressor should be cycling on/off.
Cycling is on for a while and then off for a while.
A while means around half an hour or so. I cannot give you exact timings but it should not be on for a couple minutes and then off for a couple minutes.
The temperature in the freezer should be ok as there is ice coming out from the ice maker. There is noise heard all the time. Sometimes big, sometimes little. I suspect the big noise comes from the compressor. When the noise became little I noticed the fan was still running, but not sure if the compressor was still running.
The temperature in the freezer should be ok as there is ice coming out from the ice maker.
"should be OK" is not good enough.
You have to measure the temperature.
You cannot really tell what it actually is because frozen is frozen.
If the freezer is trying to get down to lets say 10 below F then the compressor will run too much and it will also cost you a fortune in electrical bills.
Best to measure it.
