Hot Water relief valve and leaking pipe

Any plumber's in the Ozb smarts bank that can comment with my leaking HWS.

We have a gas hot water storage unit (16 years old) and I have noticed more than usual that the over flow pipe seems to be leaking more constantly.

It normally trickles out a bit and then stops.

I have used the relief valve to let a fair bit of hot water out, but it is still leaking at the outlet pipe at bottom once I close the valve off. Is this normal. Should it not stop dripping.

Might explaim my higher water bill last quater.

Plumbers with ideas. What's the likely cost of a new relief valve.

Thanking all in advance.


  • +2 votes

    I am not a plumber, but I replaced the exact same item on our HWS in March 2019 and my records show the part cost $88.77 from Reece's.
    Dead simple job to replace.
    BUT, if I can recall there are different pressure settings for the valve so take a photo of the old one and/or HWS model then go to a plumbing supply and grab a new one, and also some teflon tape.


      Hey thanks for the tip. Did you just turn off the gas burner to make the change? Don't want to be giving myself hot water burn trying to get the thing off


        From memory I just turned off the water - it is only a (max) 5 minute job so leaving the gas turned on is no issue

  • +1 vote

    Yeah had to replace my pressure relief valve this year, the part was about $85 from Bunnings, was really easy to replace, just watch a few YouTube videos. Apparently you have to release the pressure every 6 months which I wasn't aware of.


      Yeah I knew you were meant to do it, but never reslky did. Did it the other week, but valve may have just gone past its use by date.. Meant to be replaced every 5 years

      • +1 vote

        5 years ago was when we replaced the whole unit so yep the pressure relief valve lasted about 5 years.

  • +1 vote

    Check eBay you could save yourself $35. It is important you replace with the same pressure rating as well as an identical valve.

  • +1 vote

    They are between $60-$110 at bunnings.

    Go to a plumbers supply and they will be cheaper. You will need to take a sample or photo and partno as there a re a few different types

  • +1 vote

    Did I dream it, but can you get a cosy for your relief valve?
    If so, how much and where can they be gotten

    And OP, on the tag there should be all these figures, just take a photo and take it to a plumbers shop and get a new one. And while you are at the plumbers shop, don't forget to get a roll of plumbers tape.
    When you get home, turn off the water, may as well turn off the power to the HWS. Undo the pipe going into the relief valve, then using your 12" shifter, undo the relief valve. Put plumbers tape on the thread of the new relief valve and go in reverse order to do the rest

  • +1 vote

    You have had a good run if the unit is 16 years old, plumber should be able to replace this for you for under $250, if you have a cold water expansion valve installed on the cold water inlet side, you should change at the same time.