The RTH110B non-programmable thermostat can be used to control gas, fuel oil or electric furnaces - 2 or 3 wires, central air conditioners - 2 or 3 wires, hot water systems with or without pumps - 2 wires, millivolt systems - 2 wires, and central heating and cooling systems - 4 or 5 wires. This thermostat is not compatible with heat pumps or multi-stage systems.
The RTH110B is a non‑programmable electronic thermostat designed for gas, fuel‑oil, electric furnaces, central air conditioners, hot‑water systems and low‑voltage systems. It supports heat, cool and off modes, with fan control options for automatic or continuous operation.
The guide covers safe removal of the old thermostat, wiring diagrams for 2‑ to 5‑wire installations, jumper settings for fan operation, battery installation, basic operation, configuration menus, technical specifications and warranty information.
| Power supply | 2 AA batteries |
|---|---|
| Maximum load | 1 A @ 24 Vac per output |
| Setpoint range (heating) | 41 to 82°F (5 to 28°C) |
| Setpoint range (cooling) | 59 to 95°F (15 to 35°C) |
| Display range | 23 to 122°F (-5 to 50°C) |
| Storage temperature | -2 to 122°F (-20 to 50°C) |
| Temperature display resolution | 1°F (0.5°C) |
| Accuracy | +1°F (0.5°C) |
| Heating/cooling cycle lengths | 10, 12, 15, 20 or 30 minutes (programmable) |
| Compressor short‑cycle protection | Minimum off time 5 minutes |
| Dimensions | 5 in. x 3 in. x 7 in. (127 mm x 75 mm x 28 mm) |
A 2‑wire heating system uses two wires.