No heating at all is different from one cold radiator; it usually points to something affecting the whole system, such as the boiler itself, the programmer, or a valve controlling flow to the radiators. We diagnose and fix no-heating faults across Cheam and Sutton.
Common causes range from simple settings issues, such as a programmer not calling for heat, to boiler faults like low pressure, a failed pump, or a stuck diverter valve. An engineer will work through these systematically rather than guessing, since more than one issue can look similar from the outside.
If your hot water still works but heating does not, or vice versa, that is a useful clue and worth mentioning when you call, as it can point towards a diverter valve issue rather than a boiler fault affecting both.
Common causes of no heating
- Thermostat or programmer not calling for heat
- Low boiler pressure triggering a lockout
- A stuck or failed diverter valve
- Failed pump not circulating water around the system
- Boiler fault preventing ignition or heat production
Checks to try first
Some checks are safe to try yourself before calling.
Thermostat and programmer
Check the thermostat is set above room temperature and the programmer is set to call for heat at the current time.
Boiler pressure
Check the pressure gauge is within the normal range marked on the boiler casing; low pressure is a common and often simple fix.
What an engineer checks
Beyond the checks above, an engineer will test the diverter valve, pump, and relevant sensors, and check whether the boiler is producing heat but failing to circulate it, or failing to produce heat at all.
How charging works
No heating call-outs are charged by time at our standard hourly rate, with the rate depending on when the visit takes place, plus any parts. See /our-rates for current figures.
