I hooked up a honeywell HE220A by-pass humidifier and the water is constantly running with the furnace on or off. I wired it the same way the diagram said using the transformer that plugs into an outlet, but can't figure it out. I have a very old furnace with a transformer that has the t-stat terminals on it and wired it to the terminals which worked fine for a few hours, shutting off the water when the furnace shut off, but then stopped working for good. When that happened I would just hook it back up to the transformer again. Any info would help thanks.

Check yor wiring, make sure you have sail or pressure switch wired in series with humidistat to humidifiers 24V power. Pressure or sail switch will disconnect humidifier when furnace fan is off. Humidifier (110V) could be connected to any closest electrical outlet.

I believe that Carrier has a 24 volt setup for humidifier but am not sure. On the circuit board I think there is a terminal (HUM). If there is this terminal connect 1 wire to this and 1 wire to C terminal.
If not,pretty sure there is a 120 volt EAC terminal. This would only kick on when blower is on. If you have to use this you would have to install transformer to the EAC connections

Hello, In order for the humidifier to turn on and off you need either a sail switch or current sensing relay. A sail switch senses air flow and will turn on the humidifier when the blower motor kicks on and a current sensing relay senses current through the blower motors common wire. If you have either of theses hooked up already and the solenoid valve remains open then the solenoid valve must be replaced.

a couple of things, is this new or old..
1. you should have hooked up to hot water side of water not cold
2. you should have summer/winter bypass installed
3. what is your outside humidly running.

Pleas rate this response with thumps up section thanks..

hook up the new transformer to the white (common) from the blower motor, and the lead from the blower motor hooked up to the heat term on the board. (just cut the wires and wire nut all three together)

it is best to use a seperate transformer for the hummidifier, but in some cases you can use the low voltage t-stat wire that runs your furnace, you will need to have one wire run to common, and the other to the heating side of your low voltage, normally its the red wire hooked to the w circuit of your terminal board, if you do decide to go with an extra transformer, make sure you you have it wired to bring on the humidifier only when the unit calls for heat, hope that helps

thanks for your question,
you have to install the bypass humidifier on the supply side of your heating system, (hot side) and run a bypass pipe from the return side, (cold side), it does matter which side it goes on, you do not want water vapor going directly into your furnace, as this can damage it and shorten the life of it, your humidistat is installed on the return side of your duct work, this will allow proper operation of the unit as the humidistat senses the moisture in the air and brings on and shuts down the humidifier as needed. hope that helped to answer your question, please let us know what you think, again thanks, mr.grzz

Sounds like you Connected the humid trans fromer directly to a main power source. It should be either on the EAC or HUM term on the board of the furnace.

if you just replace the unit and it is working, no your do not need the tranformer. The unit is getting power from the furnace. For reference though. The black and white wires are your 120 volts. Black hot, white common. the 2 screws are your 24 volts

I am having the same problem. I have had my humidifier for about 5 years now and I just started having the problem where the water continuously flows through the solenoid. I took apart the solenoid by removing the fittings from both sides. When I did that, I noticed that there was a hole in the metal that allowed me to see through to the other side. Apparently, it had corroded and and broken through, allowing the water to pass through the solenoid without really going through the valve within the solenoid. There are several sites that sell replacements for about $70, which is not cheap, but cheaper than buing a new humidifier for $120. Here is one site I found: http://www.iaqsource.com/product.php/honeywell/32001639-002/?product=112783&category=1142