24vac hum terminal

[clefhanger]

attempting to power the humidifier solenoid

There is a dedicated 24vac terminal on the IFC labeled "hum". It has 4v when the furnace is off and miniscule millivolts when unit is on. I'm not a professional, just a hard core DYI trying to figure out why this terminal is not sending sufficient power. All other hvac components are fully functional... thermostat, AC, and furnace.

What started the troubleshooting process is that the humidifier solenoid was not working. When the humidistat was set high enough for the terminals to contact, the furnace would not turn on. So i would have to turn the humidistat all the way down in order for the furnace to turn on. I don't have any other way of powering the solenoid to test it until I can get power from the terminal on the IFC.

Thank you for your help!
Les

 

[WorthFlorida]

Does the humidistat bring 24vac to the terminal or does the terminal bring 24vac to the humidistat to the humidifier to turn it on? It could be the humidistat itself. Disconnect the wire at this terminal and check voltage at the terminal and then the wire? On the inside of the furnace there should be a wiring diagram. If you can take a pic of it and provide model numbers, etc. it would be helpful.

 

[Sponsor]

 

[DonL]

There is a dedicated 24vac terminal on the IFC labeled "hum". It has 4v when the furnace is off and miniscule millivolts when unit is on. I'm not a professional, just a hard core DYI trying to figure out why this terminal is not sending sufficient power. All other hvac components are fully functional... thermostat, AC, and furnace.

I think you will find that the HUM connection is a Dry Contact. It does not put out 24vac. It just switches ON and OFF, Closed/Open. It can switch DC as well.

If the humidifier solenoid is getting voltage, The Coil may be open. Or you may have a bad connection.

Good Luck.

 

[clefhanger]

Well... This is my first foray into an IFC board. But I've figured out after learning what G, W, Y, R mean, that whoever wired this before we moved in put the solenoid common wire onto the "cold" terminal. As soon as I moved it over to the 24v common terminal... voila!!! the solenoid kicked in as it should.

Many thanks for your input!

Les

 

[DonL]

Well... This is my first foray into an IFC board. But I've figured out after learning what G, W, Y, R mean, that whoever wired this before we moved in put the solenoid common wire onto the "cold" terminal. As soon as I moved it over to the 24v common terminal... voila!!! the solenoid kicked in as it should.

Many thanks for your input!

Les

That is good.

Nice Job.

Enjoy.