Honeywell THM5421R1021 IAQ Equipment Interface Module

Product Information

I own a Honeywell VisionPRO thermostat (TH8320R1003) which is used to control my natural gas furnace through an Honeywell Equipment Interface Module (THM5421R1021). You can easily relocate a thermostat or upgrade equipment without running new wires when using this module and a wireless FocusPRO® thermostat.

At Cold Air Central, we pride ourselves on being a trusted authority in the world of HVAC supplies, equipment, and parts. Then there is the concern that my installer connected only the batteries and not the readily available 24V wiring.From mini split systems to room air conditioners and dehumidifiers and registers, you can count on Breeze33 for convenience, quality and value. Our old heat-only thermostat had exactly two wires running to it from the boiler room: red and white (connected to the R and W terminals respectively). A portion of every Stream33, Breeze33, Craft33, and Bright33, purchase will be donated to your local Feeding America foodbank.

Everything seemed to work fine so as others have stated there is no problem having both the batteries and the 24v connected at the same time. Check with your company admin to get an invite to your company's profile, then create your own account.Applications include Gas, oil, electric, heat pump, forced warm air, hot water, steam or gravity systems.