Resideo th401/u Line Voltage Non-programmable Thermostat

Product Description

The RESIDEO th401/u is a line voltage, digital, non-programmable thermostat designed for direct control of electric heating systems. It operates on 120, 208, or 240 VAC and uses an SPST TRIAC switch with a thermistor sensor for accurate temperature sensing. The vertical-mount, white housing suits standard wall-box installations. Licensed electricians typically handle line voltage thermostat replacements due to the high-voltage wiring involved. This unit is well suited for residential and light commercial electric heating applications where simple, reliable on/off control is the priority.

The th401/u is rated for use with baseboard heaters, radiant ceiling systems, convectors, fan-forced heaters, and general electric heating loads. Its multi-voltage compatibility — 120, 208, and 240 VAC — makes it flexible across different circuit configurations common in North American electric heating installations. The vertical mounting orientation fits standard single-gang wall boxes. CAN/CSA-C828-06 approval confirms suitability for both U.S. and Canadian installations.

Key Features

• Multi-voltage rated: 120, 208, and 240 VAC in a single unit
• SPST TRIAC switch for quiet, relay-free switching of electric heating loads
• Thermistor-based temperature sensing for accurate, responsive control
• Non-programmable digital interface — simple setpoint operation with no scheduling complexity
• Vertical mount design fits standard single-gang wall boxes
• CAN/CSA-C828-06 listed for U.S. and Canadian use

Compatibility

Designed for use with baseboard heaters, radiant ceiling systems, convectors, fan-forced heaters, and other line voltage electric heating loads operating at 120, 208, or 240 VAC.

Installation Notes

Line voltage thermostat installation must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and all applicable local codes. Always shut off power at the circuit breaker and verify the circuit is de-energized with a non-contact voltage tester before disconnecting or connecting wiring. Do not apply low-voltage wiring practices or control wiring to this line voltage device. Confirm supply voltage matches one of the rated values — 120, 208, or 240 VAC — before energizing the circuit.

Technical Specifications

• Series: TH401
• Voltage Rating: 120/208/240 VAC
• Switch Type: SPST TRIAC
• Sensor Type: Thermistor
• Mounting Type: Vertical
• Color: White
• Certifications: CAN/CSA-C828-06
• Application: Baseboard Heater, Radiant Ceiling, Convector, Fan-Forced Heater, Electric Heating

Standard Information

• Brand: RESIDEO
• Manufacturer Part Number: th401/u