Resideo - Honeywell Home THM5421R1021 Thermostat Equipment Interface ModuleThermostat Equipment Interface Module from Resideo Honeywell Home, model THM5421R1021, is a versatile 2 wire IAQ thermostat interface designed for reliable, hardwired control. This vertical mount, gray module supports up to 4 Heat 2 Cool heat pump or up to 3 Heat 2 Cool conventional configurations and is compatible with THX9421R5021 and Prestige VisionPRO systems. Its compact size (4 13 16 W x 1 5 8 D x 9 5 16 H) ensures a clean fit in standard

5 Cv flow capacity with a 20 PSI differential rating

Durable gasket material engineered for Beckett oil burner systems

wall-mounted zone control panel that streamlines climate management for up to four zones

Designed for reliability in dusty environments

Direct replacement for Armstrong furnace models

Whether you're servicing an existing Reznor unit or performing routine maintenance

Built for compatibility with both gas and electric unit blowers

this assembly provides proportional control to match building loads

It converts 208/240-volt mains to a 24-volt control circuit

The McDonnell & Miller 193 Boiler Low Water Cut-Off/Pump Controller is engineered to protect boilers by precisely monitoring water level and automating feed pump control

The FLEX-4 architecture enables quick swaps during routine maintenance

this assembly includes four gaskets to ensure a tight seal and prevent leaks