At Cold Air Central, we pride ourselves on being a trusted authority in the world of HVAC supplies, equipment, and parts.

Famous can help you with specifications, product options, design, layout, and coordination of your project from A to Z. Then there is the concern that my installer connected only the batteries and not the readily available 24V wiring. With our guidance on how to replace HVAC parts, even the most complex home air conditioning repair parts and DIY heating system repair projects become manageable. Right now there are absolutly no wires connected between the stat and the furnace or the equipment interface module. To learn about our use of cookies and how you can manage your cookie settings, please see our Cookie Policy.It's designed for easy installation and can be used with the THM5421R1012 or THM5421R1021U or THM5421R1021HWREDLINKEQUIPMENTINTERFACEMODULE.

When you purchase through links on our site, we may earn an affiliate commission, which supports our community. This Module will control up to 4-stages of heat and 2-stages of cool in a heat pump system and up to 3-stages of heat and 2-stages of cool in a conventional system.Honeywell's Equipment Interface Module (EIM) THM5421R1021 IAQ was supposed to help there -- hooked up to the TACO 406 ZVC in the boiler room instead of the thermostat, and talking to the thermostat via Honeywell's proprietary RedLink-protocol. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Whether you're in need of HVAC troubleshooting parts for a system that's not cooling, seeking out seasonal HVAC maintenance kits for summer AC repair parts and winter heating system upgrades, or simply looking for the best parts for AC repair and HVAC upgrade kits online, Cold Air Central is your go-to source. All this and much more is available to you absolutely free when you register; for an account, so join our community today today!