Description
The Honeywell/Resideo T1 Pro TH1110D2009 is a “set-it-and-forget-it” thermostat for homes that only need simple, reliable temperature control. It handles single-stage furnaces, air conditioners, or heat-pump systems without auxiliary heat—all on standard 24-volt wiring—so both installers and homeowners can count on trouble-free operation.
Key Features & Benefits
Works with single-stage systems
Compatible with 1 Heat / 1 Cool gas, oil, or electric equipment and single-stage heat pumps that don’t use auxiliary heat. Matches most furnaces, straight-cool A/Cs, and single-stage heat-pumps you’ll see in a home.
Flexible & reliable power options
Runs on the system’s C-wire or on two AA batteries when a common wire isn’t available, making retrofits easy. If the C-wire or power drops, AA batteries keep the heat or A/C running during storms or brownouts.
Clear, back-lit display (2.37 in²)
Large numbers are easy to read across the room, even in low light.
Front-access battery door
Change batteries in seconds—no need to pull the thermostat off the wall.
Honeywell Home upgrade ready
Part of the professional T-Series line. When owners want scheduling or Wi-Fi, a T4 or T6 body snaps onto the same plate—no rewiring, no hassle.
Wide ambient envelope
Designed to work from 32 °F to 102 °F and up to 90 % relative humidity (non-condensing). Fine for attics, garages, or damp basements.
Ideal Applications
- Homes or rentals where occupants prefer a simple dial-up / dial-down thermostat
- Light-commercial spaces with fixed temperature requirements
- Equipment change-outs where only R and W/Y wires are present, but a battery-backed control is acceptable
