heating not turning on - http://www.hvacmechanic.com/ Forums

Original message

neela

71.255.87.206

"heating not turning on" , posted Tue 25 Oct 11:26

I have gas (forced air) 2-zone central heating. one zone is working properly. Other zone , I can hear a noise but there is no air coming out of the vents. I replaced the thermostat, but that didn't fix it. Any ideas on what could be wrong?

Thanks in advance

Replies:

Freon

68.220.62.48

"Re(1):heating not turning on" , posted Tue 25 Oct 13:59

Are the two zones supplied by two individual furnaces or is there one furnace supplying both zones? If the former, you need to look at the furnace supplying the no air flow zone and see what works (do the main burners light? Does the pilot system try to light the burners?) when you call for heat. If it's the latter type of system, you'll need to trace the supply ducts that don't have air flow back towards the furnace looking for a piece (~2 feet long) of duct that has low voltage wires coming from it. That duct valve may not be opening and you need to figure out why. Is it mechanically stuck? Oil may work. Is there 24 volts power to the solenoid?

neela

71.255.87.206

"Re(2):heating not turning on" , posted Tue 25 Oct 18:07

I have only one unit. When the fan switch is on Auto, nothing is happening except I can hear the noise. When I moved the fan switch to On, I could feel the (cold) air coming out of the vents. When I open the control panel of the furnace, I don't see any flame either. So I don't understand how the other zone is working. The earliest appointment I could get is next week and I am hoping to get heat back on before then.

Thanks

Freon

68.220.62.48

"Re(3):heating not turning on" , posted Tue 25 Oct 21:25

I am at a loss. Could you have an air handler in the other zone using a heat pump with electric backup? If the furnace is not operating yet you get heat in one zone, there has to be another source of heat. You need to do some exploring and try and locate all your equipment.