how to wire bypass humidifier in infinity

danncars

hi i just have a question i been having trouble wiring a bypass humidifier(aprilaire) with a infinity furnace whats the best way to do it?

thanks

HVACDave

I think you could use the HUM terminal off of the control board for 24v power to the humidifier in series with your humidity control. That terminal should only be powered when there is a fan active in the heating mode.

If you wanted to prove air flow then you could series in a sail switch as well, but I don't think it is crucial seeing as it isn't a steam generator.

danncars

do i still use the humstat? o just control by the infinity control tstat?

raylo32

You need to wire it through the Aprilaire humidistat unless the Carrier stat has humidity sensing AND has humidity settings to control when it energizes the HUM terminal. IOW if the HUM terminal is energized whenever the blower is running in heat mode you need the Aprilaire humidistat in the loop so the humidifier runs only when needed.