Heater Furnace Help

[tomytek]

I have gas heating in my house with a digital thermostat installed. My heater will turn on for a few minutes and turn off. It never gets to the set temperature on the thermostat. The inside temperature will read 69 degrees, but I have it set for 72 degrees. The heater will turn on again after a few minutes and do the same thing. The blower does come on and the furnace ignites fine. I already tried replacing the thermostat, but the problem keeps happening. I'm going to call professional help, but I wanted to see if you guys had any thoughts before I do. I would appreciate the help.

Thanks,
Tommy

[supremeheating]

dirty flame sensor ,clean with dollar bill ok to call if needed Mike 410 365 9265

[tomytek]

Mike,
Thanks for all the suggestions. I end up calling someone to come out and take a look at it.

The tech suspected that the problem was with the limit switch. He tested it, and it tested fine. Then he made sure all the vents were open in the house. I did have a few closed. He said that closing a lot of vents could cause the limit to trip. Then he tested and the problem was still the same. Then he tested the limit again and said there is a problem with the limit. He said they had to order the part and would have to come back. After he left, everything has been working fine. Now I'm not sure what the problem actually was. The only thing different now is that all vents are either cracked or wide open. I'm going to tell them to not come back since everything is fine now. Thanks again for the help.

Thanks,
Tommy

[supremeheating]

make sure he did not take the limit out of the circuit for this is the primary safety for overheating