Blower control from second thermostat?
I need to double check the wiring of a second thermostat in my cellar to control the blower on my Bryant 350MAV furnace. I have a wood/coal stove that can push the temp in the cellar to 85 and want to push that air through the house using the furnace fan controlled by the cellar thermostat (I had a return vent installed by the stove with the new HVAC system). The way it is wired right now (by the HVAC installer about two years ago), red / green from the cellar thermostat to red / green in the furnace doesn’t seem correct to me since the A/C kicks on when the cellar thermostat calls for the blower! I discovered this soon after the install as I was sitting in my rocker, coal fire blazing, heard the blower kick on and (feeling extra smart that I had thought of this trick sooner rather than later) – reached over expecting to feel the warm air coming out the vent only to discover cold A/C air hitting my hand! My remedy was and still is to throw the breaker for the A/C in the fall so it won’t come on. This has been working fine, warm cellar air moving through the house controlled by the cellar thermostat turning on the blower. Just recently while taking down Christmas lights I could still hear a “hum†at the outdoor compressor unit when the cellar thermostat calls for the blower and figured that it wasn’t such a good sound. Is there a way to control the blower from the cellar ‘stat without going through the A/C circuit? My choices to land the wires on the furnace terminal block are Y, C, G, R & W. Right now, R & G are connected to the cellar thermostat. By the way, the upstairs thermostat works fine in the winter and summer. Thanks for the help.
Replies
Greetings bp,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someones attention that can help you with advice.
For future reference when posting, it is easier to read when the post is broken up into smaller paragraghs instead of one long block of print.
Cheers
'Nemo me impune lacesset'
No one will provoke me with impunity
Thanks for the bump & the tip. I did get an answr from another HVAC forum indicating it was wired incorrectly and should have had an isolation relay among other things. I am in manual mode....so much for automation!
Yes all this can be done, but it is not a DIY job. Not knowing all the details of your installation (i.e. not being there), it is hard to give step-by-step DIY directions and most pros will be reluctant to do so.
Yes you do need an isolation relay among other things. Recommend you hire a competent HVAC contractor.
DG/builder