Originally Posted by drptpgt
Hi, I hope you guys can help me out.
My furnace works fine first thing in the morning or when it isn't used for a few hours. After the first use, when it turns on again, the burner ignite, and after a few seconds, as soon as then flowers turn on, the burners shuts off. Anyone know what I can replace, or check? Can it be the thermostat?
Thanks in advance for any help.
If you have a digital stat they don't have heat anticipators, so that shouldn't be it. Does your unit have an ignitor or is it a pilot light system? If it has an ignitor how long do the burners stay lit before turning off? If it's less than 10 seconds your problem is likely a bad flame sensor.
When a furnace with an ignition system starts it allows the burners to run for about 7 sec. If it doesn't receive a signal from the flame sensor in that time it will shut the burners down. These are notorious for working sometimes & then not working at other times so that may explain why it seems to work in the mornings but not later on. If that's the problem the solution is simply to clean the flame senson off with a wire brush or something similar