Dripping from hot water cylinder

plumb1_2

Pressure relief valve will need changing.

robowen

keithsav wrote:

Rob,

looks something like a large red football and looks to have a pressure relief valve on top (it has a red cap on it) - is this what you mean ?

Do you know if there's a way to see if this has failed ? There is a pressure gauge on it, but the dial is in the 'green zone', even when the water and/or heating is on.

Thanks for the help so far,

Keith

If the diaphram inside the pressure vessel is split, it will fill with water, expand and the have to come out of the pressure relief valve(prv is normally seperate from the vessel). The pressure vessel(football) has a cap on it to repressurise the vessel.

You can test the pressure vessel by removing the cap and pushing the valve in similar to deflating a car tyre. (only do this if you have a tyre pump to refill vessel with air.)
If you get a small amount of air, this is good. You will need to re-pressure the vessel to the manufacturers instructions. (air, means the vessel is ok and it might be the pressure relief valve that is faulty, this will be the valve you say releases water).

The pressure relief valve is a safety valve and will act if something else fails. But as mentioned, can be faulty itself.

If you get no air, re-pressure the vessel to the correct psi/bar whatever, and try the system again.

If you get water out of the valve, the pressure vessel is stuffed.

Don't try this if you don't know what pressure to put back into the vessel, and don't try it if you have no foot pump.

rob

keithsav

Hi,

It does look like it's the temperature/pressure relief valve. The current one is a Honeywell TP192 - anybody any idea where I can get a replacement ?

Thanks,

Keith

grumbler

Just a couple of links:
My boiler keeps getting up to 3Bar and letting water out why?
http://www.plumbworld.co.uk/231-0000

robowen

grumbler wrote:

Just a couple of links:
My boiler keeps getting up to 3Bar and letting water out why?
http://www.plumbworld.co.uk/231-0000

Both links are only relevent if you have a combi boiler.

The OP has an unvented system.

rob.