We are having such a problem with our furnace at home I am hoping this site can answer my question after I explain what the trouble is.
On very cold and windy days, our furnace will not kick on. We leave it set on 74 and come home and it is 67 in the house. And you can still hear the furnace running, it just isn't blowing out heat. If we turn the thermostat down to below what the temp is in the house, say 66, you can hear it click off. Then turn it back up and it will come on and blow out heat for a few minutes, then it will shut right back off and won't come back on unless you click it on and off again. Yes, the thermostat has a new battery. Yes the filter has been changed. Yes, the chimney has been inspected for blockage. The only other thing we've thought it might be is that the chimney or flue might be too short? Is there a formula to measure this? If so, what is it, please?
We have had a new circuit board recently installed, but the furnace still has the same problems. We have also been told that it could be the blower motor going bad. We don't think this is true, because the blower motor will blow out heat all day long as long as it isn't cold or windy out. Please feel free to e-mail me at firstname.lastname@example.org thank you for any help you might be able to provide