# Wired humidifier to HUM on furnace circuit board and solenoid smoked and burned out.



## cmbezln (Apr 16, 2013)

I followed this diagram, what am I doing wrong? I thought HUM was 24v.

I did not use the transformer, as I assumed HUM and common would replace the transformer as the power supply


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## user_12345a (Nov 23, 2014)

will depend on the model of furnace, always check the service manual or check with a multi-meter prior to doing any wiring.

you'll have to get another solenoid. 

if the included transformer is one of the plug-in types and you want to take power from furnace, you can wire between W/W1 on the board and C. it will come on with a call for heat, shut off when the burners turn off and the water left in the pad will continue to evaporate.


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## cmbezln (Apr 16, 2013)

user_12345a said:


> will depend on the model of furnace, always check the service manual or check with a multi-meter prior to doing any wiring.
> 
> you'll have to get another solenoid.
> 
> if the included transformer is one of the plug-in types and you want to take power from furnace, you can wire between W/W1 on the board and C. it will come on with a call for heat, shut off when the burners turn off and the water left in the pad will continue to evaporate.


Hey thanks for the info. It's a nordyne furnace and its nearly impossible to find any service manuals for it, i'll have to test with the multimeter.

The transformer is a plug in type, but it shouldnt be necessary in the wiring for the humidifier, correct?


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## user_12345a (Nov 23, 2014)

it's necessary if you want to take power from an outlet.

if you want to use hum terminals will have to get a wired non-plug in transformer.

or wire between w1 and c.

It's ridiculous that they provide a plug-in transformer instead of a proper one which wires into the furnace. that's how it used to be.

people who can't do wiring in a furnace have no business installing them and should call a professional, instead they dumb everything down.


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## cmbezln (Apr 16, 2013)

user_12345a said:


> it's necessary if you want to take power from an outlet.
> 
> if you want to use hum terminals will have to get a wired non-plug in transformer.
> 
> ...


Yeah I'm not sure why the plug in style was included in something that's designed to power on and off with the furnace.

It's my fault for assuming the HUM terminal was regulated to 24v, but the wiring diagram from honeywell gave me false confidence. I'll have to pick up a new solenoid and transformer like you mentioned.


While I have you here, can you look at these circuit board schematics and confirm I have them wired to the correct terminals? I circled the two terminals used when I fried it.


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## user_12345a (Nov 23, 2014)

not familiar with nordyne anything, just looking at the diagram, it has a hot for the humidifier and shows neutrals which line voltage motors plug into.

hence, that's definitely line voltage only and i don't need to look further. 

the solenoid will be pricey. transformer cheap.

so either connect a transformer between humidifier terminal and neutral, wire to W and C thermostat connections or use the plug in - pressure or sale switch will turn on humidifier with plug in.

your mistake isn't that bad, could do a lot worse. (hint - don't drill or cut sheet metal in the area where the evap coil is)


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## cmbezln (Apr 16, 2013)

user_12345a said:


> not familiar with nordyne anything, just looking at the diagram, it has a hot for the humidifier and shows neutrals which line voltage motors plug into.
> 
> hence, that's definitely line voltage only and i don't need to look further.
> 
> ...


I really appreciate your help, man...you've made this a lot easier!

I just ordered the solenoid and I think I'm going to go with option #2 and use the W and C thermostat terminals and forgo the transformer. I found a random youtube video from a professional HVAC installer a few minutes ago that recommended the same thing over using the HUM connection with a transformer, so sounds like that's a sure bet.

I've also found myself going down a rabbit hole with Nest thermostat specific wiring, seems like you can control the humidifier directly with the Nest somehow, which sounds pretty cool and I've already got the Nest.

Anyhoo, I'm rambling but thanks again!


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## supers05 (May 23, 2015)

Nordyne uses 120v on their hum terminals. It's how they all were until very recently. 

The nest can't control a humidifier on a separate transformer without a relay. If you want the nest to control it, you'll need an extra wire from the thermostat. 

PS. If you haven't already connected a C wire for the nest, I highly recommend it! They tend to stop working on the coldest day. 

Cheers!


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## cmbezln (Apr 16, 2013)

supers05 said:


> Nordyne uses 120v on their hum terminals. It's how they all were until very recently.
> 
> The nest can't control a humidifier on a separate transformer without a relay. If you want the nest to control it, you'll need an extra wire from the thermostat.
> 
> ...


Thanks Supers, my Nordyne furnace is about 4-5 years old, so I'm assuming that's the case and would explain the instant frying of the solenoid. 

I gave up on the nest idea since, like you said, it require the extra wire run and I realized that its probably not a good idea since my house is trilevel and the nest is on a seperate side of the house than the bedrooms and family room, would probably make more sense to just have it go off the humidistat in the return duct to get a more accurate reading since we're hardly ever on the level with the nest. 

Although, hopefully I didn't fry my humidistat in the process, too :/

I know for sure I dont have the C wire, but I've read (from Nest themselves, even) that removing the Y1 wire in the winter circumvents this issue, so that's what I've been doing and so far so good.


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## supers05 (May 23, 2015)

cmbezln said:


> Thanks Supers, my Nordyne furnace is about 4-5 years old, so I'm assuming that's the case and would explain the instant frying of the solenoid.
> 
> I gave up on the nest idea since, like you said, it require the extra wire run and I realized that its probably not a good idea since my house is trilevel and the nest is on a seperate side of the house than the bedrooms and family room, would probably make more sense to just have it go off the humidistat in the return duct to get a more accurate reading since we're hardly ever on the level with the nest.
> 
> ...


Some people use y1 as a common in the winter. It's a messy work around.

Cheers!


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## GASCo (Jan 23, 2017)

I replied to your other thread... just copying here.

My HUM is 120V. It varies from furnace to furnace, though..

By the popping and more specifically, by the smoke, I believe you fried the board (if you had the electronic humidistat) and solenoid. 

You can still run it without the electronic humidistat but you'll need a mechanical one. If you had a mechanical one you should be good.

You can find plastic solenoids on ebay for 8 dollars:
http://www.ebay.com/itm/272051661740...:MEBIDX:IT

You'll need a valve to control the flow as well:
http://www.ebay.com/itm/291922070343...:MEBIDX:IT

The OEM solenoids have a restrictor to control the flow without a valve. This solenoid I posted opens a lot more than the stock one and will flood your humidifier if let to fully open.

On the other hand, I assume they will last longer than the 2-5 years he OEM last. Even if they don't, they are no $40 each.

Depending on how you wired the HUM, you might have lost your 24V transformer for the humidifier too.


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## supers05 (May 23, 2015)

GASCo said:


> I replied to your other thread... just copying here.
> 
> My HUM is 120V. It varies from furnace to furnace, though..
> 
> ...


He didn't use a transformer.

Your links don't work. 

Cheers!


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## GASCo (Jan 23, 2017)

Fixing the links:

http://www.ebay.com/itm/272051661740?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

http://www.ebay.com/itm/29192207034...49&var=590914257926&ssPageName=STRK:MEBIDX:IT


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## Airborne2182 (Feb 6, 2017)

Thanks for your insight. Helpful info here for others with Humidifier installation questions.


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