I just successfully replaced the transformer between the furnace and humidifier, and it appears to be working as expected. I noticed that the humidifer is connected to the main power line of the furnace, making it run 24/7. I would like to connect the humidifier lead to the furnance board so it only runs when the furnace is blowing air. I looked at the furnace board and there is a "HUM" lead. My question: I presume that is the positive; if so, where do I connect the negative? The "HUM" lead is some flat-type connector, is that a standard connector I can buy at a big-box store?

Furnace brand: Frigidaire
Furance Model: FG6RA120C

Thanks!

p.s. Bonus question: Most pictures of humidifiers I've seen are connected to the return and then feed into the heated air. Mine connects above the warm air and then feeds back down to the blower. Is that a proper installation?

 

[QUOTE=scader;1661323My question: I presume that is the positive; if so, where do I connect the negative? [/quote]
There should be two sets of HUM on the board.

One is hot side, and other one is on the nutruel side (mostly white wires going to it.)

Yes. 1/4 female spade.


Pretty large furnace you got. Must be a large home?



There is no right or wrong way. Most prefer it on the return. That way if there was an issue, the water is not going to get into the furnace and cause damage.

 

There is one labeled "HUM", one labeled "ECA" and three "NEUTRAL." The three neutral are all taken up: one by the blower, one that goes into a transformer that I believe powers the board and the third just taps into the neutral of the main power (via wiring nut). If I plug the humidifier's hot into the HUM, can I connect the neutral into the wiring nut along with the other netural (white) wires?

Not too big, 2500 sqft. I believe it's overkill, but purchased by the previous owner probably because the house has more holes than swiss cheese (and as I first-time home-buyer four years ago I didn't know to look for that). I'm doing my best to plug them up. Needless to say, it's frustrating.

Thanks for the quick response.

 

Yes.

Odd that that your board didn't have it.. I looked at the diagram, and it shows HUM on the nuertral area.

 

May I get access to the diagram for future reference? I've googled, but didn't locate one. Thanks.

 

Here is the install manual.


The board is on page 28.

 

Wow, okay, I'm really glad I used this message board before I began re-connecting the wiring. I was thinking the HUM netural was the hot; I didn't notice the real HUM hot as it was blocked from view by the blower's connector. All makes sense now.

Thanks for all your help!

 

Glad the diagram helped!

Had my wondering what was going on!

You have a great weekend!