• Please note, some of the links on our site are affiliate links (Learn More)

FFTR1821QS1 Frigidaire fridge shutting off every 20 min

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
Model Number
FFTR1821QS1
Brand
Frigidaire
Age
1-5 years
hello ,my frigidaire fridge was shutting off every 20 min without going into defrost just staying stoll,so I replaced the control board, but after replacing the board am getting same results. The fridge stays on for 30 min but shuts off just like it did before ,

I ohmed the fresh food thermostat sensor ,the reading looks good, but just to test the thermistor I relocated the thermistor to a warmer spot from the control board housing to see if the fresh food thermistor would sense warm air & keep fridge running longer ,

it looks like the compressor runs longer but when it shuts down it take long time to come back on,so that puts me in square one again, any idea what else could it be that would tell the board to shut off compressor crkt & not even go into defrost cycle,plz update
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
4,368
Location
Ontario, Canada
tech2009 said:
frigidaire fridge was shutting off every 20 min

Why is that a problem? A refrigerator is suppose to cycle on and off. That's how it maintains temperature.

What shuts off, the compressor, the fans, the lights?? Does everything shut off at the same time?

What are the temperatures in the refrigerator and freezer compartments?


tech2009 said:
without going into defrost

How do you know that it doesn't go into defrost?


tech2009 said:
it take long time to come back on,so that puts me in square one again,

Remind me again, what is square one?


Please clarify the complaint.

Dan O.
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
thanks for looking in Dan, the refrigerator compartment keeps around 48°, the freezer keeps around 8° , system shuts off everything ,no defrost occurs checked with volt meter, no comp or fans operates, the original problem was every 20mins system shutting off & stays off about 20mins ,keeping food warm , so I replaced the controll board after a test a procedure, but didnt fix problem. but I did notice a longer run time on the fridge by keeping the refrigerator thermostat in warm water , & rechecking the thermister for ohms resistance it's about 5° off in temp ,so I would figure theres something with the refrigerator thermostat. hope this clearly explain the problem.any suggestion would help
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
I want to use a manual defrost control & cold control stat & replace with currently used controll board setup on my frigidaire fridge ,is there any retrofit kit on the market that would replace a controll board with a manual defrost timer there not only cheaper in price to replace,they also last long time then a control board ,any suggestion would help
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
4,368
Location
Ontario, Canada
tech2009 said:
I did notice a longer run time on the fridge by keeping the refrigerator thermostat in warm water

What thermostat is that? I don't see a thermostat used on that model.


tech2009 said:
is there any retrofit kit on the market that would replace a controll board with a manual defrost timer

Not that I'm aware of. Besides the fact that the electronic control on that model doesn't only perform defrost functions, it is also responsible for controlling the temperature which a defrost timer has nothing to do with.


Dan O.
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
according to the wiring diagram its called fresh food thermostat ,its located inside the control board housing & its plugged to the control board, I would like to know why my fridge not keeping the refrigerator compartment cold should be around 35°-40°.
 

Attachments

  • 20201223_182646.jpg
    20201223_182646.jpg
    246.7 KB · Views: 66

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
4,368
Location
Ontario, Canada
That is the thermistor. Did you check its resistance in relation to the temperature it is sensing.

image.jpeg

That resistance is what the control uses to determine whether the cooling system should run or not. If it's relaying incorrect information to the control, there's no way the control will be able to maintain proper temperature.

LINK > FF Temperature Thermistor

I suggest it be placed in a glass of ice water and then testing to see if it's resistance is accurate and then we'll go from there. Although if you have accurate measuring device, it should ideally be tested at multiple different temperatures.


Dan O.
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
yes I have tested the fresh food thermister ,its few degrees off from the actual temp for the resistance its showing me on my meter, I went ahead & ordered new one , helpfully this should solve the problem
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
4,368
Location
Ontario, Canada
tech2009 said:
its few degrees off from the actual temp for the resistance

2 deg., 3 deg, more? What were the actual readings?? Accurate information is helpful when trying to diagnose problems.

tech2009 said:
I went ahead & ordered new one

Let us know how you make out.

Dan O.
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
sorry I dont remember off my head , the actual temperatures but it was 5° off, when I cross referenced to the chart ,i.ll update once replace the thermister , thanks again dan.
 

tech2009

Premium Member
Joined
Dec 25, 2020
Messages
8
Location
new York
hay dan update on my fridge, after replacing thermistor, the fridge section keeps around 42°-°45 & 3° on FREEZER section ,know fridge cycles 13min on & off about 20mins approx ,no fan or compressor running at this time most likely no defrost either , I think it should stay on longer to drop fridge temp down to 36°, what your opinion?
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
4,368
Location
Ontario, Canada
the actual temperatures but it was 5° off,

What would have been more useful is its reststance and the temperature it is sensing at the time. Eg. 28 deg. = 27K ohms. That's easiest by putting the sensor in a glass of ice water as you know that temperature is 32 deg. F.

tech2009 said:
I think it should stay on longer to drop fridge temp down to 36°, what your opinion?

The timing of cycles in unimportant. It doesn't run for set times, it's running should be dependant on temperatures, which vary. Don't bother timing it any longer. It doesn't help anything.

The fridge should run until the control setting are achieved... however long that takes. What are the controls set to?


PS. How are you measuring the food compartment temperature? The best way i,ve found to get an accurate measure of food temperature is to put a container of water on a middle shelf and measure its temperature. Wait 12 hours after changing the setting to measure that temperature again.

Dan O.
 
Top