BoilerTroubleshooting2026-02-26
Boiler Leaking from the Pressure-Relief Valve
PRV discharge means over-pressure, usually from the expansion vessel or over-filling.
Water from the external discharge pipe means the pressure-relief valve is releasing.
Why it discharges
Over-pressurization, a waterlogged expansion vessel, or a failed valve seat cause the PRV to release water as a safety measure.
The fix
A technician checks pressure, the expansion vessel and the valve, then corrects pressure or replaces the failed part.
Key takeaways
- PRV discharge = over-pressure
- Often the expansion vessel
- Don't cap the valve
- Needs a technician
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