multiple thermostat question

[bandit86]

my basement is cold and upper level is hot, could I install a thermostat to just turn the fan on and circulate the air when it gets below a preset temp in the basement?

this is an issue all summer and winter, would like a thermostat thats set 2-3 degrees cooler then the upper one. I'm pretty sure I can wire it parallel, but I need to figure out what wires to wire. On either heat or cool setting just the fan... could do it with diodes I guess

what's a good thermostat for this? will probably replace the upper with a nice programmable unit while at it

 

[Mark42]

Re: multiple thermostat question

Yes, that should work, although I don't know how to prevent the furnace from firing. Wiring the theromostats on parallel will turn on the furnace and blower when either thermostat turns on.

 

[ondarvr]

Re: multiple thermostat question

It can be done, the second one just ties into the fan after the relay for the heating elements. There are some components you will need to do it this way though. Many Heaters come with a fan only setting, you may be able to pick up one of those controls for your unit and and hook the thermostat to the fan only side.

I was going to do something like that, but just went with a second, smaller and quieter fan on a thermostat to move the warm air around. The ducting and fan location were easy in my application.

 

[jsfinn]

Re: multiple thermostat question

Can you adjust dampers in your heating/cooling system? They should be flip-flopped in summer and winter.

In the summer, you want more cold to be sent upstairs and in the winter you want more hot air to be sent downstairs.... Hot air rises.

If that doesn't work for you, they do make duct fans that you can install with a built in thermostat so you can push or pull air from just one room. Maybe that would suit your needs.

 

[j_martin]

Re: multiple thermostat question

On the thermostats in parallel question. Even if you have a heating/cooling thermostat, when it's in heating, on most of them the fan is then tied directly to the heat terminal. On some higher end thermostats, the heating and cooling circuits are isolated, or can be. In that case you could wire them in parallel.

Safest bet is to use a second fan relay, transformer, and thermostat.

Then again if it's a newer furnace with electronic controls, it gets complicated again, but not impossible. Just takes relays.

hope it helps
John