Furnace humidifier

[Scouter]

Humidity has been low so I dug into it to find the problem. Turns out the installer never connected it to the furnace, just ran the wires into the unit. Any idea how to determine where to connect it? Figure this is a common add-on, so thought there might be an obvious place.

[blackhat]

Depends on the furnace. Some have nothing, many of the newer units controlled by a circuit board have a terminal marked "HUM". This can be either 24v or 120v so you need to determine which first. I can walk you through this if you have a basic electric meter.

[Scouter]

Yeah, I have a meter. Also, took pictures of the control board, best as I could with all of the wires running in front of the board.

[blackhat]

I can't get anything from those pics. Is there a 1/4" male spade terminal marked "HUM" or can you get me the furnace make and model number.

[Scouter]

Make is York, here's the model and serial number.

[daddo]

With that model, you might consider a thermostat with humidity control built in it.
If the humidifier is 24v controlled all you need is the thermostat and one extra low voltage wire from the thermostat- which it looks like you have. (The common white wire you have there on the board is going to the outdoor unit).
The thermostat may have to run off of batteries in that case.

Tstats like these for example.
http://www.prothermostats.com/category.p...egory=1379

[Scouter]

Yeah, not really interested in doing that. Far more work than it should be.

[blackhat]

On the opposite side of the board from the thermostat connections are a bunch of white wires connected to terminals marked neutral. Next to them is a terminal marked "HUM". Its 120 volt switched on when the blower runs in a heating cycle. Confirm that with your meter. Set the furnace to heating and measure the AC voltage between that terminal and any one of the neutral terminals when the main blower starts. You'll have to hold the door switch in to make this happen. If it does register 120v, connect a 24v 20 VA transformer line side to that terminal and a neutral terminal. Your humidifier connects from the new transformer load terminal to the humidistat, to the humidifier and humidifier back to the other load terminal on the transformer. This is assuming your humidifier is a 24v model.

[EatenByLimestone]

You can start sealing air leaks too. Once I started sealining the house I didn't need to run a humidifier anymore. All that heated air leaving the house is money escaping! A few tubes of caulk and an afternoon will get a lot of the gaps.

[mad_planter]

My humidifier doesn't connect to the main controller, as far as I know. it has a separate humidistat that controls it, might be a simpler way to install it.