We have a 25 yr old Bryant forced air gas furnace mounted downflow.
Just in the past 3 days, we have noticed, mid-day the house, set at 70 was cold & the thermostat said it was 66. When we increased the temp, the heater would not kick back on. Verified it was not running some thermostat program & over-rode all programming & just set the house at 75. Unit still would not kick on. Changed the filter. It was clean, by the way.
Nothing. Turned it off & on at the light style switch on the outside of the unit & it came back on, kept the house up all day/night. (roughly 24 hrs) Next day, same thing. About noonish got cold & noticed the house was 65. Same routine (except the filter change) & once I turned it off & on it kicked on & brought the house right up to 74 & shut off properly. Turned it back down to 70 & kept up all night even though its been in the 20's. Today, same routine. While at work, my wife said it got cold around lunch & the house was 66. She went out & turned it off / on & it kept up the rest of the day? T-stat is a Honeywell Chronothem III, also probably 25+ yrs old. Also to mention is the blower motor sounded loud last year, but this year has sounded OK. Maybe I'm just getting used to the noise. Its not terrible, but a little squeaky

Do you know the model #? Post here if so.

Do you know the model #? Post here if so.

Bryant Model 373LAV Downdraft

I found it is flashing code 14 which is ignition proving failure

When I turn it off and on the board resets and the light goes solid manual says it resets at 3 hour intervals.

Possible board or gas valve?

Sounds like you need to clean flame sensor.on left side in front of burner. Pull it out sand it off with sand papper the wire brush put back in let us know if it works

sounds like you need to clean flame sensor.on left side in front of burner. pull it out sand it off with sand papper the wire brush put back in let us know if it works

Tee hee... Maybe its brittle or maybe I was too rough with the wire brush but now I have a Norton Model 271M LH33ZS004 sensor in 3 pieces :0

Brrrrr... wonder if these things are hard to find?

Oh, BTW, thank you for your prompt responses & advice.

Tee hee...Maybe its brittle or maybe I was too rough with the wire brush but now I have a Norton Model 271M LH33ZS004 sensor in 3 pieces :0

Brrrrr....wonder if these things are hard to find?

oh, BTW, thank you for your prompt responses & advice.


A little Google tells me this is the ignitor, huh? What does the sensor look like?

A little Google tells me this is the ignitor, huh? What does the sensor look like?

OK, OK, once you stop laughing... now I found the sensor. It's been cleaned with sandpaper before but is a little corroded. I re-sanded it & put it back in... now if I can find an ignigtor in the am, I'll let you know how it goes.

:(

OK, OK, once you stop laughing........now I found the sensor. It's been cleaned with sandpaper before but is a little corroded. I re-sanded it & put it back in.....now if I can find an ignigtor in the am, I'll let you know how it goes.

:(


New ignitor & flame sensor are in & so far so good... 74 inside, 11 out :D