Overview
- The consumer group says avoid setting TRV dials above three except in the room with the main thermostat.
- Bedrooms should be set between two and three to maintain roughly 15C to 20C comfortably.
- Setting a valve to five fully opens it, which suits the thermostat room but can push up bills if used everywhere.
- Use the frost symbol when away to keep rooms above about 7C to help prevent frozen pipes.
- Coverage includes a simple dial-to-temperature guide (0 off, * ~7C, 1 ~10C, 2 ~15C, 3 ~20C, 4 ~25C, 5 ~30C) plus British Gas advice to bleed radiators cold at the top and to recheck boiler pressure at around 1–1.5 bar when off and near 2 bar when running.