Water does not fill in the Aprilaire humidifier on my furnance

I have had several humidifiers. The larger the water tanks the better. If your water is always empty, its working fine. Just keep filling it up. A really dry house will suck up the water amazingly fast until you get a little humidity going, then it will slow down. Will make a big difference. MUST keep water in it. RJ

if your saying that the voltage drops to around 4 volts at the supply transformer at anytime , then id say the load (device connected) is too much for the transformer to supply this most likely is caused by an internal fault in the load (humidifier) also since its a water appliance id say a water leak might be a factor in that as well , taking a look under the cover of the humidifier 4 signs of a water leak (or past one) would be where id start

its going to drip when it is off,it has built up humidity and has nowhere to go,leave it running and let it cycle by itself or cause damage to the system

I would check the shut off valve from the supply line, it is probably plugged or off. If on then I would guess it is one of the tube piercing valve types which will fail. Be sure the supply line has pressure.

You need to reset by turning thermostat dial all the way to test reset. It will reset itself, then go back to your setting.

My humidifier has a knockout inside the hose connection, that you have to remove. simple but check it out.

the refrigerant r134a has leaked out,you need to have it recharged,this is normal for most de-humidifiers after 2 to3 years of use

Make sure you unplug the unit first. there should be screws at the base, in the back, or underneath the humidifier. Once you remove all the screws the cover should come off as one big piece. Careful when removing the cover, however, as there may be ground wires attached to it . Usually if you vacuum out the inside godd and around the copils that may help with performance. You can also buy a special acid that you can spray on and rinse off with water that removes alot of residue.

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Also, Don't forget to pull the plug, shut the water valve and drain the unit. A unit with a water reservoir should be drained and cleaned with white vinegar, a mix of one part chlorine bleach to eight parts water or muriatic acid. Mist-type humidifiers also require regular cleaning to remove mineral deposits.

If you bought a dehumidifier, you will not need to put water in it. A dehumidifier removes water. A humidifier add moisture to the air, and you need to add water to this. Was your dehumidifier running before and then it stopped? If so, it will have a tank on the bottom that will have water in it that needs to be emptied out. Let me know if this is your problem.

This model furnace does not come with a built in humidifier. Humidifiers are normally an optional add on. If you have a by-pass type humidifier it is none adjustable. Water level is normally float controlled and operation is control by blower circuit. When ever the blower runs the humidifier operates when in the heating mode.