Temperature & Pressure Relief Valve Replacement

What this service covers

T&P relief valve replacement is a safety-critical repair for unvented hot water cylinders. The aim is to restore correct protection against excessive temperature and pressure.

• Confirming the fault and checking the cylinder make and safety ratings
• Isolating and safely depressurising the unvented system
• Removing the failed T&P relief valve and fitting a like-for-like, correctly rated replacement
• Checking the discharge route via tundish and pipework for safe operation
• Re-pressurising, testing for leaks and verifying correct valve operation
• Recommissioning the hot water system and confirming normal performance

When this is the right service

Book a T&P relief valve replacement if you notice water discharging from the tundish, recurring pressure-related leaks, or a valve that will not reseat after lifting the test lever. It is also suitable where the valve has seized, is corroded, or has been flagged during unvented cylinder servicing. If you are a landlord or manage a small premises, replacing a suspect safety valve helps reduce the risk of breakdowns and non-compliance.

How the replacement is carried out

The engineer will identify the correct valve specification for your cylinder, then isolate the water and heat sources and reduce pressure safely before removal. The new valve is installed to the required rating and sealing method, then the system is refilled, vented and brought back up to operating pressure. Final checks confirm that the cylinder heats normally and that the safety discharge path is clear and behaving as it should.

After the job: keeping the system safe

Once replaced, you will be advised on any related issues found during testing, such as problems with pressure control components or the discharge pipework. If your cylinder is due a service, it is often sensible to schedule this so safety devices and controls can be checked together. Ongoing maintenance helps prevent nuisance discharge and supports safe long-term operation of unvented hot water systems.