I hooked the humidifer up and water keeps running it dose not stop when furnace stops. What might be wrong?

It sounds like it is just miswired. The low voltage wiring off the humidistat should be on W and C on the circ. board at the furnace. If you have it on R and C then it will power it constantly regardless if the heat is running or not. W is only energized on a call for heat which is typically when you want that type of humidifier to run

Do you have a sail switch or current sensing relay with this humidifier? In order for the humidifer to turn on and off u need either a sail switch that senses airfllow in the return air duct and will turn off the humidifier when the blower motor stop or a current sensing relay that senses current on the blower motors common wire. I will post of pic of each one

Sail switch


Current sensing relay

you need tocheck for power at solinoid valve or continuity of valve where water enters the unit. THe furnace must be on and humidistat calling...

these are flow thru models and a lot of water passes thru them. The instructions say to not limit the water by closing valve at all!

theholts220 - Sounds like they needed to install a bit larger transformer . You can also buy a A 50 Sensing relay that attaches to the wires for your motor and when you turn on the furnace it will allow the power to go to the humidistat. Very strange though they do not use a lot of power. Check and make sure the wires are not pinched or touching metal somewhere.


TLuzzo - The humidistat seems to be working when you turn it down. The wires for the solenoid should be hooked up to your furnace circuit board. The instruction manual will tell you where. If you dont have a spot on your circut board the A 50 sensing reley is they way to go. They are inexpensive

When your unit is on normal the outside unit works and the inside only the fan runs. your heat pump does not remove any humidity when it operates so the installation cotractor did not wire it to operate then. you can change the wiring on the humidifier to operate all the time by wiring it to the fan (g) terminal then it should work just turn it all the way to the lowest humidity when you are in cooling mode.

It is possible you may have wired it wrong. Make sure your humidifer is not robbing power from your thermostat. This would explain when your humidifer makes a demand to come on it robs power from your t-stat making it lose its call for heat. Wire your humidistat to the "w" terminal and the common terminal so it only runs on a call for heat. With the bypass type of humidifier you purchased it wont do you any good to run when the heat isn't running anyway. If you want an independent operation humidifier you need a steam type.

Replace the water valve... It"s vibrating when closing. Do you have hot water feeding the unit?

The water is only dispensing over the evaporator pad while the furnace is in the heating mode. When the furnace finishes cycling the humidifier will also stop.

You can try installing the water line to your hot water if it is installed on cold line for more humidification. You should make sure your humidistat is up line 6" @least from humidifier for proper humidification measurement.