49 High
Your boiler has shut down because the water returning from your radiators has become too hot, usually caused by a circulation problem.
Technical description: Return sensor high temperature intervention
Typical repair cost: £120-280 (including labour)
DIY fix possible
Check that at least two or three radiators have their valves turned fully openEnsure your central heating pump is running and hasn't seizedCheck the system pressure gauge and top up to 1.5 bar if it is low
Protect yourself from future repair bills
A boiler cover plan would cover faults like 49 — no call-out fees, no surprises.
*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.
Parts commonly replaced
- Circulation pump
- Return NTC temperature sensor
- Main heat exchanger (flushing service)
*Affiliate links — we may earn a commission at no extra cost to you.