Furnace Not Igniting

Problems related to residential installations.

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Furnace Not Igniting

Post by deanofadmission » Thu Apr 16, 2015 10:37 am

Ignitor/Burners not consistently lighting. It sometimes works, sometimes doesn't. Fan always runs. Thermostat is fine. The LED error light doesn't blink, it's just constantly red. It's a Bryant Plus 90 furnace.

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- Furnace Not Igniting

Post by hvactrainingspot » Fri Apr 17, 2015 4:09 pm

It is possible that you have a flame sensor that is not proving flame. The unit is flowing gas but then it doesn't ignite and shuts down. The fan shouldn't always be running unless you have the thermostat switched to the "FAN ON" position. Usually you would receive a blinking error code if there was a flame sensor fault. Once the unit kicks on, check to see if the ignitor ever glows and if gas flows. If gas is flowing and the ignitor doesn't glow then you may have a bad ignitor. If the ignitor glows but it doesn't light, then check the ignitor positioning and gas pressure.

I hope this helps!
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- Furnace Not Igniting

Post by Freon » Fri Apr 17, 2015 4:24 pm

Let me ask a few questions so I understand your problem.
"The Fan always runs." Is this fan the smaller draft inducer fan that begins immediately when you want heat or is this the fan that circulates warm air in your house?

"Ignitor/burners not consistently igniting." Do you see the ignitor glow bright red every time you call for heat? Do the burners ignite and then go out or do the burners not ignite in any way?

The more you tell us, the better out answers can be. Observing your furnace when it's trying to heat your house and not succeeding is most important.

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