i found this in an old thread and tried it, but it doesn't work:


"If you have more than two wires available, connect one of the spares to the "G" terminal on the thermostat & the same color to "G" on the circuit board. Putting a jumper between R & G on the board will make the fan run all the time but you would either have to turn off the switch or remove the jumper to make the fan stop. There would be no control from the thermostat. "

The thermostat HAD only two wires hooked up. The furnace (LP) worked normally as far as heating goes, but the "Fan Only" would NOT make the fan run. I realized there were only two wires hooked up. (Red and either black or white, I forget).

I took the advice above, looked behind the thermostat, realized that what I though was only two wires, had additional conductors available that were not in sight. So I looked at the diagram inside the furnace door, and it showed which color wires to hook up to the thermostat and the furnace. I had to add to wires into the mix. I added the (G) wire to both the themostat, and the furnace, and I added the (Y) wire to both.

Then on the thermostat (ritetemp), I switched it from OFF, to heat, then switched the "Auto Fan" setting to "Fan On" (or fan only), still no fan.

What I am trying to accomplish, is, on the hottest days, at the peak of the day's heat, is just run the furnace blower for about 20 minutes to bring the cool air up from the basement for a short while.

I noticed on the back of the themostat there is a jumper that has two options, Furnace and MTC (or something like that). The house has no AC. Which setting should that be on? It was on MTC (or whatever it is). Should it actually be on 'furnace'? What is the function of that jumper?

Also, if I just want to run the furnace blower, what setting do the thermostat need to be on?

I thought the fan only switch was like a master override, and would just force the blower on no matter what... no?

Thanks for any insight.

 

What's the model number on the furnace and stat?

 

It seems that your thermostat is wired wrong, particularly if it has always functioned that way. If you can look at the wiring diagrams, and know how to troubleshoot, it should be a simple fix.

Just a question. Why do you want to run "fan only"? Theoretically, it will increase circulation throughout the house - when there is not a call for a/c or heating. Personally, I haven't found it very useful, but all systems are different - and maybe it would be a help for you. It will, of course, increase electrical usage to run the fan when a/c or heat is not called for.

 

Normally the "cold air" returns take the air from the living area, not the basement. All you will do is recycle the warm room air. A window fan would be a simpler way to stir the air.

 

a window can can't pull the air up from the basement to the first and second floors. and the furnace is in an old unusual farmhouse so 'normal' things aren't normal.

 

the temps in the house get hotter than outside temps. trying to help kids survive summer. basement air is COLD. Want to blow it upstairs at the hottest part of the day. not sure why this doesn't seem to be making sense to some.

 

The return duct would have to be opened to the basement and the return air would have to be closed to the living space.

 

N V G 9 1 0 0 F H G 1 - MODEL NUMBER.



Comfort maker

 

can we focus on why Fan Only doesn't work?

 

Try this : put the heat cool off switch to off. Then put fan switch to on.

 

In your abnormal farm house, lets say that your plan works and you pull the basement air up to the living areas. You now create a vacuum in the basement and the blower quits delivering air - unless you replace the air from somewhere. Where would this make up air come from? My guess is from the upstairs or outside or a mixture of both. It would be better just to live in the basement during the heat of the day.

 

@skaggsje I thought the thermostat had to be ON for the fan to work, no?

 

No. The thermostat is always on. Think it as a switch, or set of switches for the furnace.

The "heat-cool-off" switch controls if the furnace is in Heat mode, Cool mode, or off. (Neither heat or cool)

The fan switch is either on, or auto. "On" turns the fan on independently from the furnace. "Auto" turns the fan on when the furnace starts to heat or cool the house.

So the wiring between the stat and the furnace should be the same wires and the same terminals:
R = power
W = heat
G = fan
Y = cool

 

That is what you posted in your first post and is correct.

I'm not going to argue your logic for trying to run the fan in the summer. I can't find any service info on the model number you posted. I can help you if you post the wiring diagram or a picture of the area where the thermostat wiring connects at the furnace.