Bryant furnace turns flame off before set temperature is reached.
I have a Bryant Induced-Combustion Gas Furnace, model 373LAV Downflow & 383HAV Upflow. Mounted horizontally. It turns off flame before set temperature is reached, and recycles immediately.
Sequence is:
Inducer starts
After 25 sec. the ignitor glows
After 8 sec. the flame lights
After 45 sec. the blower fan starts
After 2 min. 21 sec. the flame goes out
Indicator light flashes 33
After 5 sec. the inducer fan stops
After 3 min. 58 sec. the blower motor stops
Inducer starts immediately
And it's the same cycle over again.
Clean filter, and no intake restrictions.
Doesn't appear to be cracked heat exchanger (no blowback)
Flames are blue and appear to be confined to the exchanger ports (no roll-out)
Thermostat anticipator has not affect
RobertShaw mercury switch thermostat level
I cannot inspect the vents close-up, they are in high ceiling. But, I cannot detect much air from the vents.
It is 20 degrees F outside. The thermostat is set to 72, but the temperature does not get above 64.
What do you think?