Coleman Gas (7665-856) Not warming house

[heartsfull]

The blower was replaced a year ago. I have now replaced the valve, fan switch and thermocoupler and the pilot is clean. The air coming from the vents is about 70 degrees. The fan area of the furnace is cool, yet above it...near blower and above is hot. Seems the hot air is going outside. The burner stays fully ignited, yet the fan turns off after only a few minutes. The temperature in the house never comes even close to the set temperature on the thermostat. Any suggestions on what to do next?
Thanks,
Michelle

[Robert]

Hi Michelle,

With that many problems and parts replaced and it being a gas furnace, you need to get a Tech to test and diagnose it.

Need to find out why blower motor shuts off early. Why heat seems to be going outside.


Could be a dirty furnace chamber, blocked burner orifice as part of problem for example.


Thanks,
Robert

[heartsfull]

Thanks
We did have a tech out (for the third time actually, two different ones) and he seemed to be pulling at straws (he replaced the thermostat) ...so I took it where he left off so to speak. He said it may need a new valve so I replaced that. But it was still doing the same thing. So I tested the fan switch and it was bad, so I replaced that with an adjustable one. Still the same problem. Not sure how much having a tech come out again is going to help me with what they have done so far. What is left to replace really? Maybe I should just replace the furnace?

[heartsfull]

Sorry me again....
"blocked burner orifice" Would the pilot fully ignite if this were the case?

[Robert]

The pilot is seperate. Burner can ignite, but not get complete gas pressure and burn and therefore not get complete heat build up in chamber.


I would not call them back, but would try to find a reputable Tech who is competant and not into parts guesstimating and changeouts.


You cannot fully grasp what it is or is not doing without proper equipment/tools and knowledge to test and fully diagnose the operational values.


It being gas and under these circumstances, would be dangerous to you for me to attempt it from here.


Thanks for inquiring,
Robert