T3R battery-operated, wall-mounted thermostat features a large LCD display, 7 or 5/2 day programs with up to 4 time and temperature changes/day, optimisation, boiler service timer, automatic summer/winter change, manual and timed-override and frost protection (Off) mode. Designed to provide automatic time and temperature control of heating systems in homes and apartments. Compatible with 24-230V on/off appliances such as gas boilers, combi-boilers and heat pumps. Suitable for zone valve applications but not with electric heating (240V).