A/C Operation Question
Posted: Tue May 08, 2012 3:14 pm
I have a Coleman 7995-856 gas furnace in my home to which somebody added an A/C unit before I purchased the place. When they did the A/C installation they used a Nordyne 901994 A/C Blower Relay Control http://www.mobilehomerepair.com/media/i ... 1994-5.pdf connected to a 2-wire digital thermostat.
When the furnace is in heating mode, everything works fine, but when I switch the furnace and the stat to cooling mode, the A/C runs continuously. Upon inspection of the furnace, I noticed that when in heating mode, the thermostat closes the relay and sends the signal to the furnace to initiate the heating cycle. But when everything is in cooling mode, the A/C runs with the thermostat contacts OPEN and shuts down when closed. Is that the way it should work? If so, I'm not sure what kind of stat I'm going to need to make this work.
Long story short, I'm trying to control the A/C with a typical, programmable heating/cooling thermostat. Is there some reason this won't work?
Thank in advance for any assistance you can offer.
When the furnace is in heating mode, everything works fine, but when I switch the furnace and the stat to cooling mode, the A/C runs continuously. Upon inspection of the furnace, I noticed that when in heating mode, the thermostat closes the relay and sends the signal to the furnace to initiate the heating cycle. But when everything is in cooling mode, the A/C runs with the thermostat contacts OPEN and shuts down when closed. Is that the way it should work? If so, I'm not sure what kind of stat I'm going to need to make this work.
Long story short, I'm trying to control the A/C with a typical, programmable heating/cooling thermostat. Is there some reason this won't work?
Thank in advance for any assistance you can offer.