How do I force my furnace fan to run?

Question

I have a main floor cold air return and one in the basement. I would like to be able to run my fan once at night and circulate the cooler air from the basement to the main level.

I have a Lennox Whisper Heat furnace and a Lux programmable Thermostat.

The wiring leading to my thermostat has red, white, blue, green and yellow wires.

The terminals on my thermostat are RC, RH, W, Y & G.

RC is jumped to RH. The red wire is connected to RH. The white wire is connected to W. The blue, green and yellow wires are cut short.

What do I need to do to get my blower to run when I set the fan to on?

Any help would be greatly appreciated.

Answer 1

Your themostat should have a manual/auto (or run/auto) switch on it.. If you switch it to manual or run, it should run

Answer 2

you should still have a bypass switch to be able to run just the fan without heat.i have done this many time for the same reason and at my old house when i heated mainly with a  wood stove i used the furnace fan and ducts to distribute the heat through out the house.the switch should be on the thermostat

Answer 3

In your case with just "Heat" it would be very difficult .

If you had a combination heat and cool system "Fan on Hand"

would put the fan on hi speed.

But on just a "Heat" system the fan will not run until the chamber get up to a certain temp. so as to not blow cold air and even when the thermostat is satisfied for heat the fan will run until the chamber cools down some.

The only way to get that fan to run would be to put a bypass switch across the thermal control that closes to run the fan. To do that you would have to go into the heater unit and you shouldn't attempt that unless you really are capable.

Answer 4

Flip the switch on your thermostat to "auto".  The fan should turn on.

Answer 5

when we had our furnace installed, I had the tech instal a switch on the furnace for the fan. check the sides of your furnace to see if there is a switch