How Often Should You Open Your Pressure and Temperature Relief Valve on Your Hot Water Service?

What Is a Pressure and Temperature Relief Valve?

The pressure and temperature relief (PTR) valve — sometimes called a TPR valve — is a critical safety device on every hot water system. It's designed to release pressure or temperature if either exceeds safe operating limits, preventing the tank from failing catastrophically. Every storage hot water system has one, usually on the side of the tank near the top.

How Often Should You Test It?

The PTR valve on your hot water system should be tested every 6 months. Testing involves manually lifting the lever on the valve briefly — water should flow freely from the discharge pipe and the valve should reseat (stop flowing) cleanly when you release the lever. If the valve drips after releasing, it may need replacing. If no water flows when you test it, the valve may be blocked or seized — it needs immediate attention from a licensed plumber.

Why Testing Matters

A PTR valve that fails to operate correctly is a serious safety risk. Hot water systems operate under pressure — a tank failure caused by a blocked relief valve can be explosive. In addition, PTR valves that have never been tested can seize over years of non-use, making them unable to operate when needed. Regular testing also confirms the discharge pipe is clear and directing water safely away from the unit.

Signs Your PTR Valve Needs Attention

Watch for: the valve weeping or dripping continuously (may indicate excessive pressure in the system or a faulty valve seat); water staining on the wall or floor near the discharge outlet; the valve releasing water in large amounts without being manually triggered (indicates the system is over-pressurising); or a valve that's obviously corroded or damaged. Any of these signs require a licensed plumber to assess.

ATC Plumbing carries out hot water system inspections and PTR valve replacements across Melbourne's south-east. Call 1300 282 758 for same-day hot water service.