My Aprilaire 560's solenoid started making a terrible noise a few years ago, so I turned off the water and humidistat and have been using portable humidifiers past few years. Got sick of that. I set about to diagnose the problem and found that this year, the solenoid was just dead. I hooked it directly to a 24V source, and it just hummed. So I ordered a replacement (along with a new line filter), and it arrived, and it made a good clicking noise when hooked/unhooked to 24V, so I knew it was good. Installed it, dialed on the manual (#4016) humidistat, but the solenoid would not engage. ugh. I checked the voltage at the source on furnace, around 24V when the furnace was on, as expected. I disconnected the solenoid wires and checked the voltage coming through the humidistat, and it was only about 2V. Removed humidistat and cleaned well (it was really dusty), no difference. Connected the two leads normally hooked to humidistat, and humidifier works fine, solenoid engages. So I have now ordered a replacement humidistat. So I am thinking-- is it common that humidistats burn out? Was it the low voltage coming through the humidistat which burned out the solenoid? How to test whether a humidsitat is working properly (check the resistance)? What to check to make sure this doesn't happen again? I am just a hack do-it-myselfer, moderate knowledge of electrical concepts. thanks for any insights!

I live in Toronto Canada and I'm looking for replacement filters for my Bionaire Ultrasonic humidifier. Any suggestions. Alternatively I can order them from the allergytech web site but my first preference is to go to a store. Thanks in advance. T.