How to Test Refrigerator Defrost Thermostat & How it Works!

Thank you brother. You’re videos are very helpful

Thanks

My defrost thermostat is stuck in the closed position. I heated it in hot water to see if it would open and it did not. Would the computer stop the defrost cycle anyway after a certain time? If it does this, would the computer then not go into defrost mode until reset? My fridge was totally frozen up and I thought the defrost thermostat would be stuck open?

funny thing is that even if test good for continuity it can still bad in the inside? what is the test for then

Great video! Love the detail. Thank you!

Evaporator? My thermostat switches on a heating element which melts the ice build up. Very informative however.

Thank you Sir, your video is very helpful and informative. Your instructions were clear and easy to understand. What you shared is going to save many people money and trouble. People like you make a better world. Please keep up the good work. Best regards, Laming

This video explained it so much better than any of the other top videos. They all said "IF CONTINUITY, WORKS OK" but there could be more than one problem with a thermostat.

Best explanation of these things I have ever seen!

Great explanations

Hi, Doesn't the defrost thermostat control the defrost heater which in turn melts the ice from the evaporator?

I had to cut mine out like the one in your video and it's at room temp and it's beeping, so glad for your video because now i know that is a bad defrost thermostat, ordered a replacement hope it works, thank you

Mine apparently works, because I've no issue with my refrigerator being 10 year's old getting to cold or not cold enough. My issue is, recently the water which is supposed to drain out, becomes frozen and cause's the defrost water to enter the refrigerator. I found a fix, wrapping a piece of solid copper wire around the heat tube and down into the drain hole. But I assuming it's only going to be a temp fix. What cause it to work, but apparently not sufficent enough to keep the defrosted water from draining.

Thanks bro! Simple and excellent explanation. I learned something new by your video. Great!

I have a GE fridge and I believe I need a new defrost thermostat. There is one within two degrees of the on & off temperature of the original. Essentially, isn't this just a switch that opens and closes with temperature changes? Thanks

Thanks Bro 👍

You should tell people always to test probs first. Defective prob will send you on a goose chase.

I got a question I replace the defrost heater, and the Defrost Thermostat was on there too. 1 week later the frig was 50+ replaced the Defrost timer. Frig was 35-40' now about 5-6 days later, the frig back up to 50'+ And they is frost on the Freezer, (0'-10' normal) All parts are GE. Could the defrost thermostat be bad? (NEW GE Parts)...I was thinking of using the old thermostat of the old unit. (Which one bottom heater burn out, 2 top/bottom, for this unit side by side 1997 models GE TFX25JRBBWW) Beep, at room temp, put in ice water no beep. Wait 1 hour to see if beeps again?

Thank you

Just wanted to say thanks for making such a thorough vid. I have a working knowledge of electronics from doing computer repairs, and this made it so I didn't have to have an expensive repair visit. $30 and done!

Thanks for the video. My defrost heater keeps burning out every 5 months or so. I think that it is staying on too long. If the defrost thermostat is not working correct will that cause the heater to burn out eventually? As I understand it, the defrost thermostat is sitting there....already closed when the defrost cycle starts. The defrost heater heats up. When temperature reaches certain temperature....the defrost thermostat opens....thereby stopping the heater. Once the temperature drops to a certain temp the defrost thermostat closes and is ready for next cycle. Is this your understanding?

Excellent! Thanks!

I got the new one but the cables are different color from the original, do I connect with the similar color? Is there any problem ? Of + or - ?

Dear Flashback,
You are certainly a master instructor in the you tube classroom. I will follow your testing procedure, and hope to solve my problem. I installed two timers to no avail, and there is always a frost buildup on the evaporator. Another sign that you are a gift to all us students; you reply to all the comments. Thank you, and blessings from New Rochelle N.Y.

Very well explained!
Thank you sir!

NO, the defrost heater will come on.

Good job describing defrost failed condition and then showed the actual multimeter test. Bonus is physical examination of the thermostat/thermodisc itself.

Thanks for this video .
My fridge when I plug in the wire the fridge light inside the fridge working but the fridge compressor and the little cooling fan the one next to the copmressoer not running ?

could some fridge makers design the heater circut to ground out existing current to turn heater on while others makers have a design tha just complete the circutt? or could the guy too lazy get off the couch walk 20' to get his model # just hop on ebay and order any thermostat? although if one was n/o and the n/c it would prob be labeled on package. just have a hard time wondering why the world cant agree on anything except the antarctica treaty and now way ur ice box operates

hi there
nice video
i have a whirlpoo double door model 20RI-D4 A+ PT refrigerator
the compressor and both fans are off
the fridge is not on standby I checked the control panel, it's showing both temperatures
cheked the relay it seems ok

what can be the problem please?

thanks

Some refrigerators have timers and those open and close the circuit to the element that heats up.

i have a 1999 fridge thats got one like that are they interchangeable? i ended up buying "4387503 Refrigerator Bimetal Defrost Thermostat Replacement Part by Blue Stars - Exact Fit for Whirlpool & Kenmore Refrigerators - Replaces WP4387503 343917 61002113 PS11742474 AP6009317" on amason in hopes it will work sicne nothign wants to say it works with that old of a modle number but its got the butter tub shaped one like this as well not the little stick

Thanks you helped a lot ❗

Thanks, Bro my thermostat stuck open frost build-up & the timer works. I'm not sure but my heater has 30 ohms I think this is ok?

Hi bro, does a 2 door refrigerator , the bottom door not cold enough , but at the top( freezer )works fine. Means the bimetal thermostat is at fault?

Changed mine out this morning then decided to check the continuity on the old one I had continuity when it was room temperature indicating closed and on low side as well. as far as I know I have not had and overworking evaporator. if anything it has been under working because I have build up of frost and drinking water line dispenser freezes up. Now I just wait and see if it starts working properly. Your thoughts on closed Circuit at both ends of the temp range?

I noticed water damage to the base molding by my fridge and water on the floor. When I opened the freezer I noticed some frost on the evaporator coil so I just changed the defrost thermostat today and will see if that solves it. When testing the old and new thermostats I couldn't get my multimeter to beep to test continuity on either one. I placed them in ice water for a few mins then tested the leads but no beeps. Even though the new one didn't beep I went ahead and installed it today. I'll check my coils again in a couple of days to see if I'm still getting frost on them.

Very helpful information. Thank you for taking the time to share your knowledge.

Excellent attention to detail in explanation. Very well done sir!

Thank you!

Hi flash. I got nothing on mine - it`s in ice water. Nada - zero. My voltmeter has no Sound on continuity, but the display reads zero. If I put the meter on ohms - it reads 01.5. So it`s bad?

Thank you sir. Very helpful. I never understand why videos like this get dislikes. If someone is trying to help you save money by doing it yourself , then they deserve recognition. To the 68 that disliked this video, enjoy paying the mechanic $200 dollars just to look at it. Thanks again.

Very good explanation! I liked it very much. Thanks

Thorough explanation, excellent video!!!

Thermostat I have has no numbers on it. It is plain. Why is that?

This video helped so much. My thermostat was blown almost in half from the failure that it had. The part is around $25 - 30 ish with tax at the parts store. Ordering online is probably cheaper but trying to fix it immediately instead of waiting a day or two for the part to come in.

When it closed the heater is on, but not evaporator is on.

Nice intro music. Where can we hear the full track?

I think when he says evaporator he means defroster.

My Kenmore cold spot turns off and won't come on until I turn off thermostat and turn back on. Usually have to do it 3 or 4 times to get it back on.