How does transformer hook up

It sounds like the wiring for the humidifier may not be correct. The solenoid valve, which controls the flow of water to the humidifier, should be wired to the humidistat and the transformer, not to the furnace or fan. It is possible that the bottom wire of the solenoid is connected to the wrong terminal on the transformer or humidistat, or that the top wire is connected to the wrong terminal on the humidistat. I recommend consulting the installation instructions for your specific humidifier model, or consulting a professional HVAC technician to verify the correct wiring.

Bypass Humidifier HE225 265

Check the manual and the support options. This is a water valve that is not sealing

It's not uncommon for duct work in an older home to Bang as the furnace cycles due to age. The humidifier banging while turning on and of is mostlikely the solenoid valve; if the solenoid is bad it is actually to your benefit to replace the entire humidifier as the solenoids are very expensive, 50%+ of a new humidifier. Plus you get the 5 year parts warranty on the new unit instead of just one year on the solenoid. If you don't want to replace the entire unit you can replace the Humidistat, and that should fix the on/off cycling, however a new humidistat is included with a new unit, which again is more cost effective. They are easy enough to replace as a do it yourselfer, especially when replacing an existing unit. I hope this helps you.

Hello, i have a link for a unit that will be close to what you are looking for http://www.amazon.com/Honeywell-Whole-House-Bypass-Humidifier/dp/B002XVYMDA

Hello, in order to turn your humidifier on with the furnace the 120 volts coming from your humidifer you must hook it up to a step down transformer, then the transformer will provide 24 volts to you humidistat and solenoid valve. So you need a wire from the HUM on your control board to transformer primary side and a wire from neutral on the board to primary side of transformer. Then you need low voltage wire from secondary side of transformer to humidistat from humidistat to humidifier.

I have a Honeywell humidfier HE 220A with a KIP U147112 valve. Will turning the large screw head on the valve decrease the volume of water flow through the humidifier. Too much water is being wasted.

Could be a couple of things. Transformer can be bad. Try connecting the two wires (usually wired red and white) from the transformer to terminal W and C on the circut board. Your bypassing the transformer and if installed a current sensing relay. The furnace transformer will/should handle the extra load. Turn on the furnace, if still not working, loosen the water supply line at the water solenoid on the humidifier, if water flows out then your supply valve isn't clogged, if no water then try screwing in the needle on the supply valve all the way in then back out. If still no water then the valve is clogged. If all is good then it looks like the water solenoid is bad or wiring to valve/humidifier control. Don't find the controls bad that often. Have fun!

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

control board has eac terminal . will provide 110v to hum transformer anytime fan running.

also can pick up current sensing relay to sense blower power up and will then power the Hum. transformer.

I also had the transformer problem and it was made worse but an HVAC guy who rewired the furance fan to get more air flow when he installed a new AC unit. He left the humidifier wired to the old fan windings which were now putting out 160 induced volts. The humidifier transformer, which was already undersized by Honeywell, never had a chance. Not sure how common this problem is but I later saw several references to the same problem on other websites and it's worth a quick check of the supply voltage to your humidifier.

Since I had an expensive humidifier and a whole cut in the furnace duct, I looked for a fix. My solution was to buy a $15 transformer from a BigBox that matched the voltage and was oversize on amps and mounted it externally to the humdifier (much like a furnace transformer is typically mounted). I then completely removed the piece-of-junk humidifier circuit board and wired the transformer directly to the water solenoid which it controlled and wired the fan and new transformer directly to 120V that is controlled by a current sensing relay (Aprilaire A50) on the furnace fan wires (and also controlled by a humidistat located on return air plenum).

It has worked fine for two years now, runs only when the fan is on and when the humidistat is asking for more humidity. A relatively cheap fix that would have only taken an hour if I had done it right from the start.
For those of you who haven't bought the Honeywell 360A yet - don't. For those of you like me that spent the money and cut holes in your duct - this is one solution.

Maybe Honeywell will wise up and redesign their transformer PCB to be much more robust. The rest of the unit is a pretty good design.