Resideo

Resideo controls and parts: the Honeywell Home product line under its current name. Thermostats, gas valves, ignition assemblies and components, aquastats and wells, zone valves and actuators, pressure relief valves, switching relays, transformers, fan and limit controllers, sensors and low water cut-offs.

Most of what is here is a replacement part, and Resideo parts are model-specific. Gas valves and ignition assemblies in particular are matched to the appliance and often to a serial range within one model, because the manufacturer revises the component without changing the appliance name. Order from the data plate, not from the appliance description.

Two things that decide the right part. Voltage: low-voltage (24V) controls drive a system through a transformer and relay and cover most gas and hydronic equipment, while line-voltage switches 120V or 240V directly and belongs to electric baseboard and radiant — connecting one to the wrong system is a fire risk, not a malfunction. And an aquastat has to be paired with the correct immersion well, seated to the bottom with conducting paste, or it reads the air in the well and responds late.

Working from an older Honeywell part number? The model numbering carried over when Resideo was spun off in 2018, so a number from an old manual will usually identify a current part. See the Honeywell to Resideo part number cross-reference for the full series index — L, V, VR, Q, ZD, TH and the rest, and where each sits in the catalog.

Browse Resideo controls by function

Hydronic zoning

Valve-zoned systems change the hydraulics as zones close, so most failures show up at the powerhead rather than the valve body. Replacement heads swap without draining the system.

• Zone valves — all types
• 2-way zone valves
• 3-way zone valves
• High-head zone valves
• Fan coil zone valves
• Zone valve replacement heads
• Zone valve parts
• Zone dampers
• Forced air zone panels

Boiler and hydronic controls

The aquastat and its immersion well are ordered together — well length and bulb diameter have to match, and the sensor seats to the bottom of the well.

• Aquastats and wells
• Pressure reducing valves
• Thermostatic mixing valves
• Air separators
• Boiler trim kits
• Thermostatic radiator valves
• Radiator valves

Gas and ignition

These are the parts most often ordered wrong. Match the gas valve and ignition assembly to the appliance data plate, including the serial range.

• Furnace and boiler gas valves
• Gas ignition components
• Pilot, burner and ignition parts
• Thermocouples and thermopiles
• Oil burner controls

Thermostats

Check voltage before anything else: 24V low-voltage for gas and hydronic equipment, line voltage for electric baseboard and radiant.

• Thermostats — all types
• Non-programmable thermostats
• Programmable thermostats
• Smart thermostats
• Line voltage thermostats
• Thermostat accessories
• Thermostat wire

Relays, transformers and switching

• Switching relays
• Relays
• Transformers
• Contactors
• Fan and limit controllers

Air and water

• Air cleaners and filters
• Dehumidifiers and humidifiers
• Leak detection valves

Popular in this collection: Resideo L4029E1029/U Limit Control, Resideo T498B1512/U Baseboard Thermostat, Resideo CHW3610W1001/U Water Leak Detector, Honeywell Home FocusPRO 5000 TH5110D1022/U.

Frequently asked questions

Is Resideo the same company as Honeywell Home?

Resideo was spun off from Honeywell in 2018 and makes and supports the Honeywell Home product line. Many part numbers are sold under both names, so an older Honeywell number usually identifies a current Resideo part.

Which thermostat do I need for electric baseboard heat?

Electric baseboard and radiant heaters need a line voltage thermostat that switches 120V or 240V directly, such as the T498 series. A 24V low-voltage thermostat cannot be connected to a baseboard circuit. See line voltage thermostats.

What does a manual reset limit control do?

A limit control shuts the burner off when the temperature at its sensor reaches the limit setting. A manual reset model stays off until someone presses the reset button, so the cause of the overheat gets checked first. See fan and limit controllers.