Aprilaire 800 with Carrier Infinity thermostat


Old 12-08-20, 04:05 PM
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Replace TrueSteam with Aprilaire 800 (Carrier Infinity system)

I have a Carrier 58MVC furnace with 2 stage heat pump. It is controlled with the Infinity control thermostat, I currently have a Honeywell TrueSteam humidifier installed in the following configuration:

I am looking to get rid of the TrueSteam (piece of junk!) and go to an Aprilaire 800. However, I am not sure how to wire the control wiring. The 800 only has two HUM terminals (humidistat), which I'm pretty sure go to the contact side of the existing relay (the 800 has dry contacts like the TrueSteam does). There are no other control connections on the 800 that I'm aware of. So I do not know where I would connect the R and C wires from the furnace. Do I need the R and C wires connected to the Aprilaire 800? If so, not sure where they would go. What do the R and C connections do on the TrueSteam? Any input is appreciated.


Last edited by hitt0006; 12-08-20 at 05:17 PM.
Old 12-09-20, 01:01 PM
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Welcome to the forums.

You won't need the R and C.
Connect your two relay wires..... blue(3-6) and brown(1-4) to J12-1 and J12-2 on the Aprilaire 800.
Old 12-10-20, 05:55 AM
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That's kinda what I thought. Thank you!

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