S.53 High
Your boiler has temporarily stopped working because it cannot detect enough water flowing through the system to operate safely.
Technical description: Appliance is within the waiting period of the block operation function due to water shortage
Typical repair cost: £100-280 (including labour)
DIY fix possible
Check if the black handles on your external filling loop are fully closedEnsure all radiator valves are fully openGently bleed air from your radiators using a radiator keyCheck that the system pressure gauge is between 1.0 and 1.5 bar
Protect yourself from future repair bills
A boiler cover plan would cover faults like S.53 — 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
- Central heating pump
- Water pressure sensor
- Main heat exchanger (flushing)
*Affiliate links — we may earn a commission at no extra cost to you.