Rheem Classic 90 Humidifier Trouble

norcim

I have a Rheem classic 90 furnace with an Aprilaire 600 humidifier. The furnace is 2 years old and the humidifier is 6 or 7 years old. This year when I tested the humidifier nothing happened. So before calling the hvac company I thought I would take a look. What I found seems a little strange. The humidifier is wired through a transformer to the EAC contacts on the ifc, which as far as I can tell from reading the manual, means the humidifier will only run at higher fan speeds rather than whenever there is a call for heat. Why wouldn't they use the "humidifier" contacts also on the ifc? Is this the proper way to wire this humidifier? I just want to make sure it's done right. I had a lot of problems with the furnace installation and no longer trust this company. Thanks for your help.

flashheatingand

If the humidifier was wired throgh the EAC contacts on the control board, it was a mistake. Maybe the installers were trying to do something different, but around here, we wire the humidifier through the heating circuit. One can wire the humidifier through the hum contacts on the control board, but we just do it through the heating circuit.

norcim

Thanks for your reply. That doesn't suprise me at all. I'v had more than a few problems with the installation and this is a pretty big Rheem dealer in our area.

hf05

not to familiar with that circuit board butwhen the blower relay kicks in the eac terminal will be energized,not really a biggy except in cooling mode hum may kick in depending on weather which means you must turn humidistat off at end of cooling season.really should be on hum terminals good luck..

hf05

i mean at the end of heating season oops

norcim

Turns out the hum on this furnace is a relay you wire between 24vac and the humidifier. So that the humidifier will be powered durring the heating cycle.