Thermostat/Manual Fan Switch - Contractor Talk - Professional Construction and Remodeling Forum

jocobe · 01-16-2009, 02:00 PM

Hey HVAC Pros-
I'm a window and door contractor and need a little help with a trade I am not skilled.

I have a Trane Propane Furnace/heatpump/AC unit, a few years old. The thermostat is a Trane Weathertron Baystat240A.

Everything works fine except I cannot turn on the fan manually from the thermostat. I have an Aprilaire humidifier and would like to run it more then when just the heat comes on.

The humidity in my house right now is about 15%.

Any ideas?

Thanx!
John

Dr Heat · 01-16-2009, 03:46 PM

Check to see if the G terminal on your stat is connected to the G on your furnace

jocobe · 01-16-2009, 04:25 PM

Quote:

Originally Posted by Dr Heat

Check to see if the G terminal on your stat is connected to the G on your furnace

Thanx...I'll check it out. It worked at one time, but has stopped for some reason. I'll recon tomorrow......

cleveman · 01-16-2009, 06:33 PM

What is your location and please put it in your profile?

Will it do much good to run the fan without the heat on? I have a friend with a boiler and he installed ductwork and AC for his first floor (unfinished bsmt) and he put a humidifier in the ductwork, hoping to just run the fan in the winter. There is no furnace on this, AC only. He said it is hopeless.

Checked your filter/wick thing?

jocobe · 01-17-2009, 08:51 AM

I replaced the water panel in the humidifier.

I'm wondering now, if the Aprilaire will even 'kick on' when just the manual fan switch is turned on. Does the furnace need to be operating in order for the humidifier to operate? I'm not sure how they are wired.....

John

cleveman · 01-17-2009, 10:26 AM

From what I've seen, when the blower motor kicks on, this opens up the water valve. This is done through the control board or with a "sail switch" in the return air duct. If you have a sail switch, it will be a little box mounted on the return air.

I guess the other thing to worry about is if you run your fan continuously, water will be flowing continuously.

I've had humidifiers which could really get things wet in a hurry. But now I'm experiencing some troubles with one at a friends house, and it sounds like you're having some trouble with your Aprilaire.

We'll see what shakes out.

Dr Heat · 01-17-2009, 11:25 AM

humidifiers can be wired many different ways so it is impossible to say without seeing it.
However; running a humidifier without the heat on is a waist unless you use a steam generator like a Honeywell true steam.
I suppose you could also put a pan of water on the stove. LOL

cleveman · 01-17-2009, 03:31 PM

I thought you were calling it a honeywell untrue steam.

Dr Heat · 01-17-2009, 05:06 PM

Quote:

Originally Posted by cleveman

I thought you were calling it a honeywell untrue steam.

yep that why I mention the pan of water

exphvac · 01-21-2009, 09:06 PM

You need the Honeywell 8000 (I think that's right) thermostat. You need the outdoor sensor with a varible speed fan in the furnace to work properly.

jocobe · 01-22-2009, 08:10 AM

Quote:

Originally Posted by exphvac

You need the Honeywell 8000 (I think that's right) thermostat. You need the outdoor sensor with a varible speed fan in the furnace to work properly.

Thanx! For whatever reason the fan only manual switch started working again. The Aprilaire definitely does not work with just the fan on manual mode. Thanx for the thermostat suggestion, but I just went out and bought a console evaporation humidifier for the room that has the wood stove.

The humidity is already better in the house....