Afternoon... first timer... was hoping someone has some furnace repair knowledge... Unit is a Carrier Updraft... Burner lights until its time for the blower to come on... sometimes it goes out exactually when blowers starts... other times it will stay lit 10/30 sec. after start of blower... blower runs normal run-time, but of course its blowing cold air... I changed thermostat... nothing changed... any ideas?. any help would be greatly appreciated
Thanks again
power1966wagon

Age and efficiency of furnace?

Thanks for the response... 1981... 80%
Thanks

Does the furnace have a pilot light. Carrier uses what is known as an auto pilot which has 3 wires, white, green and yellow that come out of the pilot assembly. It doesn't sound like the burner is running long enough to trip the main limit so I would suspect the auto pilot is dropping out voltage to the main gas valve.