furnace only blows heat for 5 seconds then shuts off...
#1
unit only 3 yrs old. electronic ignition. new thermostat. blows great blue flames for about 5 seconds then shuts down.could a bad (dirty) filter cause this?cycles again and tries again with same result. help!!! thanks everyone....
#2
Hi scott:
No, the burner would run longer than 5 seconds before the furnace overheated from inadequate air flow. I think the problem is related to the ignition system proving the main burner has fired. There are several types & brands of ignition systems in use. If you can give us an idea of what kind of system you have, we might be able to come up with a solution. Also, check the ground and polarity on your furnace. Electronic ignition systems have to have the right polarity and good grounding. [by polarity I mean that the hot wire goes to the hot terminal and the nuetral wire goes to the nuetral terminal] If this is all a mystery to you, it's probably time to call your servicer. Thanks. John.
No, the burner would run longer than 5 seconds before the furnace overheated from inadequate air flow. I think the problem is related to the ignition system proving the main burner has fired. There are several types & brands of ignition systems in use. If you can give us an idea of what kind of system you have, we might be able to come up with a solution. Also, check the ground and polarity on your furnace. Electronic ignition systems have to have the right polarity and good grounding. [by polarity I mean that the hot wire goes to the hot terminal and the nuetral wire goes to the nuetral terminal] If this is all a mystery to you, it's probably time to call your servicer. Thanks. John.