My Aprilaire 560 doesn't shut off even if the blower is off.

the float may be bad or sticking allowing water to run continusly even when unit is off.

Hello, sounds like rhe solenoid valve is stuck open. This will keep water flowing through the humidifier even if the Furnace is off. The solenoid valve will have to be replaced.

Hello, if the blower is off and the water keeps flowing most likely the solenoid valve is bad and must be replaced.

sounds like you may have it wired to a continuous power source vs one that shuts off with the furnace. The most common wiring is red to C & white to W

HI sounds like you have found it

Hi check power at transformer / valve on water line could be stuck open clean valve out or transformer holding valve open

Here's a link to the manual for your Aprilaire model 560 humidifier you can download and print for free.

According to Aprilaire, it is normal for there to be excess water going into the drain pan. However, the drain pan should have a drain line connected to it so the contaminents from the humidifier can be flushed down a drain and away from the unit. (see page 2 Principle of Operation).

They further state that the water valve should only be either fully on or fully shut off and do not attempt to regulate water flow with the inlet supply valve.

http://www.aprilaire.com/themes/aa/en/manuals/Humidifiers_Owners_Manual.pdf

I would give the unit a good cleaning of the pan, locate the drain connection and attach a drain line to your unit as is required for proper operation and function/

Hope you find this Very Helpful - Best regards!

i have an aprilaire model 550 im getting no water to the filter but i am getting water to the solenoid

This sounds like, the 550 transformer is not connected to the blower motor power connection (in parallel)

water trough on top filling up. do not clean it too much as crud distributes water across top better.