Resideo ythm5421r1010 Equipment Interface Module Kit

Product Description

The RESIDEO ythm5421r1010 is an equipment interface module kit that includes two duct sensors and is designed to expand the staging and control capabilities of both heat pump and conventional HVAC systems. The module bridges the thermostat to multi-stage equipment, enabling up to 4 stages of heat and 2 stages of cool in a heat pump configuration, or up to 3 stages of heat and 2 stages of cool in a conventional system. It is intended for installation by licensed HVAC technicians in residential and light-commercial applications where staged heating and cooling control is required.

The ythm5421r1010 kit is suited for zoned or multi-stage HVAC installations where the thermostat alone cannot directly manage all equipment stages. The two included duct sensors allow the module to monitor supply or return air temperatures, supporting more precise system staging decisions. This makes it a practical solution for heat pump systems with auxiliary heat strips as well as conventional gas or electric furnace setups that require additional staging beyond standard two-wire thermostat control.

Key Features

• Supports up to 4 stages of heat and 2 stages of cool in heat pump systems
• Supports up to 3 stages of heat and 2 stages of cool in conventional systems
• Includes 2 duct sensors for supply or return air temperature monitoring
• Interfaces between the thermostat and multi-stage heating and cooling equipment
• Compatible with RESIDEO equipment interface and staging control architectures

Compatibility

Designed as an OEM-style equipment interface module kit for use with RESIDEO-compatible multi-stage heat pump and conventional HVAC systems requiring expanded staging control.

Installation Notes

Installation should be performed by a licensed HVAC technician. Power down the air handler, furnace, and outdoor unit at the disconnect and breaker before beginning any wiring work. Mount the module in a location accessible for future service and route low-voltage wiring per NEC guidelines and the equipment manufacturer's wiring diagram. Verify all staging jumper settings and sensor placements match the system configuration before restoring power.

Technical Specifications

• Heat Stages (Heat Pump): Up to 4 stages of heat
• Cool Stages (Heat Pump): Up to 2 stages of cool
• Heat Stages (Conventional): Up to 3 stages of heat
• Cool Stages (Conventional): Up to 2 stages of cool
• Included Accessories: 2 duct sensors

Standard Information

• Brand: RESIDEO
• Manufacturer Part Number: ythm5421r1010