Aprilaire 550 Humidifier - Answered Questions & Fixed issues

If your water is suddenly evaporating into limescale, your local water company may have switched to a different water source, or your water softener device is out of salt. The limescale can be easily cleaned with vinegar and a sponge, but this will keep occuring unless you use water that doesn't contain disolved calcium. Try getting an RO water filter and use that water.

If the water stops when the heater is not running then the humidifier is working fine. I know it seems like alot of water but that's how it's designed.

You should have a dial setting usually on the return duct box near where your filter goes. It is probably about the size of your thermostat. Set at around 40%

It's probably the saddle valve. The self-piercing needle rusts and clogs the water line. Replace the saddle valve with a non self piercing one. Also, check the voltage to the solenoid valve on the humidifier. You should be getting 24 ac volts. If not, replace the transformer. If voltage is present and still no water, then replace the solenoid valve (very expensive).

your drain pipe is clogged up, going to drain- Duh

I had the same problem with my new furnace. it was a crack in the blower fan housing . that was 12yrs ago. it is starting to act similar now. it just will stay running like it is blowing out gas and then restarts occasionally.

1/4" flexible copper pipe. Tap into your cold water line using the included saddle valve (pierces the pipe), attach the 1/4" flexible copper pipe to the saddle valve on the cold water pipe and the solenoid valve on humidifier unit using the included compression fittings. Tada!

Hello, this can be either a clogged drain line or the tubing supplying the water into the humidifier is cracked. The size of the house has nothing tomdo with the water leaking into the Furnace.

Typically when the water continues to run after the blower cycle stops, the solenoid valve is stuck open and will need to be replaced.

Hello, usually this is a sign of a drain problem or the water is entering the humidifier too fast. If the water is not draining at the end of the drain line something is preventing the water from flowing. I would also make sure that there is no heavy mineral buildup on the water panel pad this can cause water to leak out of the humidifier. Lastly check to make sure there is a orifice inside the supply water tubing leaving the solenoid, if not this causes the water to enter the humidifier too fast.

Hello, disconnect power to the solenoid valve if this does not shut off the water flow, replace the solenoid. If it does shut off the water flow most likely the humidistat is bad amd will have to be replaced.

Hello, turn the water off at the saddle valve and turn off your Furnace. Then disconnect the wires from the solenoid and disconnect the supply water tubing from the solenoid and the outlet tubing, now unscrew the solenoid and replace it with new one and reconnect everything and open saddle valve and turn Furnace back on.

Hello, if there is not voltage at the HUM and Neutral terminals when the blower energizes than the portion of the board is bad that controls the humidifier, but you can get around that by just adding a transformer and a current sensing relay.

Hello, seems like there is no way to turn on the humidifier. There would either need to be a new transformer installed, a current sensing relay, or a sail switch to activate the humidifier when the blower motor kicks on.

Hello, apply power directly from transformer to solenoid valve, it it does not turn on the solenoid valve must be replaced. If there is no voltage to the solenoid then follow the wires back and see where there is no voltage.

Here is a link to parts for your humidifier http://www.aprilairehumidifierparts.com

Hello, I like to apply voltage directly to the solenoid valve to see if is working. Just take the two wires from transformer and connect to solenoid valve, if the valve clicks and water starts flowing the valve is good

Hello, sounds likemyou have either a bad humidistat or solenoid valve, disconnect the wires from the humidistat if this turns off the humidifier than replace the humidistat. If not the solenid valve will need to be replaced,

Hello, yes the transformer will get a 120 volts from the Furnaces control board, there should be a terminal labeled HUM on the control board. You need to bring 2 wires one from HUM and one from a nuetral tap on the board to the line side of the transformer, this way every time the blower motor on the Furnace turns on the humidifier will aswell.

Yes, it happens fairly often. The solution is to flush the system with a 50/50 solution of White Vinegar and Bottled Distilled Water. And clear the outlet line, running from the bottom of unit.
Also check any opening to the tank that would allow dust and lint to enter the tank and seal them, if necessary with duct tape. If the furnace is in a dusty area, do the best that you can to eliminate the dust.

Hope this helps you to solve the problem.