BoilerLeak Repair2026-01-06
Boiler Leaking Water: Causes and Repairs
Boiler leaks usually come from the pressure-relief valve, pump seals, fittings or the heat exchanger.
A leaking boiler should be addressed quickly to prevent corrosion and water damage. The source determines the fix.
Common leak points
The pressure-relief valve (often from over-pressure or a failed expansion vessel), pump seals, pipe fittings, and the auto-air vent are the usual suspects. A leaking heat exchanger is more serious.
What to do now
If it's leaking heavily, switch off the boiler and the water supply to it, and call for repair. Note where the water appears — it helps the technician diagnose faster.
Key takeaways
- Turn off the boiler and its water feed if leaking heavily
- Note the leak location for the technician
- Recurring PRV drips often mean an expansion-vessel fault
- Don't ignore small leaks — they corrode the unit
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