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rogerb917 · Oct 10, 2012, 10:49 AM

I have a two year old Bryant furnace (355CAV042080) and Evolution Control thermostat (SYSTXBBUID01).

Last year and again this year, shortly after turning on the furnace, the thermostat displays:

SYSTEM MALFUNCTION
CALL TECHNICIAN

After pressing the RIGHT button on the thermostat the following is displayed:

FN 9/30/2012 9:03AM F
33- LIMIT FAULT
9 EVENTS ACTIVE

F=FAULT

The furnace continues to operate and warm the house at the set temperature. I cannot set or change the temperature from the main screen because of the MALFUNCTION message, although I can change the settings through the SCHEDULE menu.

My question is: Is this a known bug with this system? How can I clear the fault so the main display returns to normal, since the fault does not appear detrimental to the furnace's operation?

I don't necessarily want to call a service technician every year just to have him reset the fault and clear the display.

Frdaly · Nov 23, 2014, 05:14 AM

Originally Posted by rogerb917

I have a two year old Bryant furnace (355CAV042080) and Evolution Control thermostat (SYSTXBBUID01).

Last year and again this year, shortly after turning on the furnace, the thermostat displays:

SYSTEM MALFUNCTION
CALL TECHNICIAN

After pressing the RIGHT button on the thermostat the following is displayed:

FN 9/30/2012 9:03AM F
33- LIMIT FAULT
9 EVENTS ACTIVE

F=FAULT

The furnace continues to operate and warm the house at the set temperature. I cannot set or change the temperature from the main screen because of the MALFUNCTION message, although I can change the settings through the SCHEDULE menu.

My question is: Is this a known bug with this system? How can I clear the fault so the main display returns to normal, since the fault does not appear detrimental to the furnace's operation?

I don't necessarily want to call a service technician every year just to have him reset the fault and clear the display.

Any help would be greatly appreciated

bitters · Nov 23, 2014, 01:18 PM

Pull the stat off and remove batteries that should clear the fault. Does the furnace stop when you see the code? Could be the limit opens and the fan keeps running to cool it down and restarts. Make sure you have a clean filter. If it happens again look through the site glass on the furnace and see if there is a flash code.