FGHB2735NF0 Frigidaire Refrigerator will not go below 56 degrees

Patriot8318

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18
Location
Arizona
Model Number
FGHB2735NF0
Brand
Frigidaire
Age
6-10 years
Our fridge will not go below 56 degrees. Freezer is at 0.

I found the defrost thermometer blown, replaced. Fixed defrost issue.

I replaced the thermistor on the fridge, both control boards, and the fan works. The air diverter is working and it's open so air should be cooling the fridge but it's not. There is no visible blockage..I'm lost.

Please help me figure this out, thank you in advance.
 

rickgburton

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Press and hold the Freezer temperature up (∧) pad and down (∨) pads simultaneously for ten (10) seconds.

Press Fresh Food up (∧) to advance thru the menu options;

Press ‘power on-off’ to initiate the selected test.

Run the following tests:

Test 12: VCC condenser Fan
Push ‘power on-off and the fan motor will run at full speed. Push ‘power on-off again and it will stop running.

Test 15: Evaporator Fan
Push ‘power on-off’ and the fan will run at low speed. “LOW” will show in freezer display. Push ‘power on-off’ and the fan will run at full speed. “HI” will show in the freezer display. Push ‘power on-off’ again and the fan will stop running and “Off” will show in the freezer display.

Test 22: Damper test
Push ‘power on-off’. The damper will open and “OP” will show in freezer display. Push ‘power on-off’ again. The damper will close and “CL” will show in the freezer display.

Test 29: Fresh food thermistor
Push ‘power on-off’ to change between F and C. The display will show the actual temp if the thermistor is good and “OP” or “SH” if the thermistor is open or shorted, respectively.

Test 30: Freezer thermistor
Push ‘power on-off’ to change between F and C. The display will show the actual temperature if the thermistor is good and “OP” or “SH” if the thermistor is open or shorted, respectively.

Test 33: Ambient thermistor at main control board.
Push ‘power on-off’ to change between F and C. The display will show the actual temp if the thermistor is good and “OP” or “SH” if the thermistor is open or shorted. NOTE: If “Er” is shown in the display, replace the main control board.

Test 34: Ambient thermistor at user interface. (* on some models)
Push ‘power on-off’ to change between F and C. The display will show the actual temp if the thermistor is good and “OP” or “SH” if the thermistor is open or shorted. NOTE: If “Er” is shown in the display, replace the main control board.

Press and hold the Fresh Food temperature up (∧) key for up to ten (10) seconds. The control will beep and service mode will deactivate.
 

Patriot8318

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Arizona
*Update: read it wrong and I was able to go through the diagnostic. Everything checked out and is functioning properly according to the test.. now I'm really lost.
 

rickgburton

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OK, leave the machine plugged in and running and remove the evaporator cover. Take a few pics of the evaporator coils and post them here. Be sure to reinstall the evaporator cover or the machine will not cool.
 

rickgburton

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That's a good frost pattern as far as I can tell. So everything is working. The machine says it's 56°F in the fresh food section so here's the 64 dollar question, Is it 56°F in the fresh food section??
 

Patriot8318

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That's a good frost pattern as far as I can tell. So everything is working. The machine says it's 56°F in the fresh food section so here's the 64 dollar question, Is it 56°F in the fresh food section??
I put a manual thermostat in the fridge to confirm and the temperature is the same as what it reads on the fridge..
 

rickgburton

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Is the cover on the evaporator installed? I just want to double check the facts. The condensor coils are clean and the condensor fan motor is running and the compressor is running. There's no gaps in the door seals. The evaporator fan motor is working. The damper is working and all the thermistors are good. Is this correct?
 

Patriot8318

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Is the cover on the evaporator installed? I just want to double check the facts. The condensor coils are clean and the condensor fan motor is running and the compressor is running. There's no gaps in the door seals. The evaporator fan motor is working. The damper is working and all the thermistors are good. Is this correct?
Yes. All you mentioned above is correct.
 

rickgburton

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OK, you're missing something. One of those components is not working correctly. In your first post you said
Patriot8318 said:
Freezer is at 0 .....diverter is working and it's open....
The evaporator fan motor is pulling that 0° air across the evaporator coils, which are much colder, and blowing into the fresh food section. If that was true you wouldn't have a problem. So either the fan is not working when it it suppose to, the damper is not opening, or the compressor is short cycling. If the compressor is running the condensor fan and the evaporator fan will also be running.

I just remembered a similar problem I had years ago. The light switch was bad and the lights stayed on with the door closed. A 40 watt light bulb can put out some heat. I don't know if you have a regular light bulb or LED lights.
 

Patriot8318

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OK, you're missing something. One of those components is not working correctly. In your first post you said

The evaporator fan motor is pulling that 0° air across the evaporator coils, which are much colder, and blowing into the fresh food section. If that was true you wouldn't have a problem. So either the fan is not working when it it suppose to, the damper is not opening, or the compressor is short cycling. If the compressor is running the condensor fan and the evaporator fan will also be running.

I just remembered a similar problem I had years ago. The light switch was bad and the lights stayed on with the door closed. A 40 watt light bulb can put out some heat. I don't know if you have a regular light bulb or LED lights.
I ran those tests you sent me a link to and the damper works, so we can rule that out. It stays open because the fridge is reading 56-60 degrees.

My guess is the condensor fan is not running 100% of the time for some reason. When I open the freezer drawer the fan shuts off and the light kicks on. As soon as I push in the drawer switch the light goes off and the fan kicks back on, is this normal?

I was getting close to installing after market fans on those square holes in the fridge to draw in more air..I'm desperate.


Is there suppose to be a very noticeable amount of air coming from the freezer into the fridge? With the condensor fan running and the freezer door shut I don't feel a "breeze" coming into the fridge from the damper or the side holes..
 

rickgburton

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You should feel air from the freezer blowing through the center. The sides are return ducts. Check for a blockage or frost inside the air channels. The fan in the freezer is the evaporator fan motor. Check and see if the door is closing the door switch. You said it works with your finger make sure the door is actually closing the door switch.
 

Patriot8318

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You should feel air from the freezer blowing through the center. The sides are return ducts. Check for a blockage or frost inside the air channels. The fan in the freezer is the evaporator fan motor. Check and see if the door is closing the door switch. You said it works with your finger make sure the door is actually closing the door switch.
The drawer is activating the switch. I'll check for blockage but I doubt there is any.
 

rickgburton

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You should feel the air in the back where the damper is. If you feel the air from the front the damper is closed and the evaporator fan is blowing it through the return vents.
 

Patriot8318

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You should feel the air in the back where the damper is. If you feel the air from the front the damper is closed and the evaporator fan is blowing it through the return vents.
So I just got home and checked it again. It seems when it hits 58 the damper closes and the fan kicks off..acting like it is at the right temperature.
 

rickgburton

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Let's check the FF thermistor even though the test says it's good. The food compartment thermistor is located to the right of the center shelf support bracket, just above the crisper on the back wall of the food compartment. @ 56°F the thermistor should have about 16.9KΩ. At room temperature or 70°F, 11.8KΩ. If the thermistor checks good the main board must be the problem. Did you replace this board:

 

Patriot8318

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I replaced both thermistors and installed a new board. Now the fan quit working all together. I put the old board back in and its throwing a sy ef code.
 

rickgburton

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Run test 15 Evaporator Fan Motor with new board installed. Check if the fan motor is getting 12V.
 
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