Hot Water Heater Pressure Relief Valve Leaking Guide

The temperature pressure relief valve  leaking is quite a common problem with all electric and gas water heaters. It is also quite straightforward and cheap to replace but please do as leaving it could cause potential problems down the line.


Why you need to solve the water heater leaking from relief valve problem

If your temperature pressure (TP) valve is faulty and stops working, then your water heater potentially becomes very dangerous.

Water Heater Pressure Relief Valve Leaking

A temperature relief valve attached to a hot water heater.


The temperature pressure valve basically relives pressure that is built up in the tank (like steam coming off a kettle). If it cannot relive the pressure then your water heater will keep increasing in pressure until it mechanically fails. When it fails it REALLY fails and can explode!

ALWAYS remember to turn your electricity off if you have a electric water heater – failure to do so will lead the risk of electrocution.


Water Heater Pressure Relief Valve Leaking Solutions


Blockage in valve

Occasionally the relief valve will have something inside of it, be it grit, dirt or maybe even a little rust.

Firstly get a container. Hold this container underneath to catch the leak. The TP has a lever, you need to flip the valve lever. In many cases this should dislodge any blockages.

However, if the valve is very old though you may not want to do this as it will may never close again. For very old water heaters, recommendation is to call a plumber or if confident replace the valve (very cheap less than 20 bucks).


Temperature too high

The overly hot water will cause the extra pressure. Simply turn down the heat via the thermostat and observe if that has any affect. Try it in increments of 10 degrees.


Location of TP valve

Location of TP valve

Water pressure is too high

If the leak is intermittent, then this would suggest that the water pressure in your tank is too high. (remember to try to lower the temperature, as this causes increased pressure) .

This could be an expansion problem (see next paragraph) or simply that the main house pressure is too high.  Consult expert advice about lowering the house pressure


Expansion problem

A less than common water heater leaking relief valve problem.

Your heater when in demand for a period of time (say a bath) and is then stopped. The water inside the tank is heated and cooled.

When this water is reheated, this water will expand and cause a pressure increase. This increase will cause the  relief valve to ‘lift’ and this will cause the leak.

The solution here is to purchase an expansion tank, but first  consult expert advice before doing so.


Worn out valve

Generally speaking, if the leak is continuous it is indicating that the valve is worn out. Simply replace it yourself or consult a plumber. Do this quickly as the dangers are great if it completely fails.


Leak intermittent/continuous

Quick test:

  • If intermittent probably a pressure or temperature problem
  • If continuous you will probably have to replace the valve


Consider getting a replacement TP valve

Consider getting a replacement TP valve

Hot Water Heater Leaking From Pressure Relief Valve Temporary Fix

As a temporary fix you could always use some Teflon or thread tape to restrict the leak. Turn the water, gas or electricity off. Slowly unscrew the valve (slowly so to release the pressure safely) and apply the thread tape. Re-screw the valve slowly and apply some plumbers putty. This will help until you obtain a plumber.

Please remember that you have hot water leaking from pressure relief valve, so turn off the water supply and let the water cool down!


Action to take

These are the main reasons on why you have a water heater pressure relief valve leaking. In conclusion if the leak is continuous may be time to replace it, if not there are a variety of solutions you can try like turning down the heat or flipping the lever. The best advice though is to always seek professional help.