Combi Boiler- leaking

[dexterulo]

Boiler leaks when hot water is switched on for bath. It also loses pressure when boiler is turned off over night. When the heating is on it goes up to 3 bar on the gauge.

Problems have stated since we bled the radiators. Can anyone diagnose the fault? Does it need to be re-pressurized?

 

[stevetheplumber]

sounds like it needs pv repreasurising and probably a new prv

 

[SafeGasInstall]

looks like need to be seen by a engineer

 

[Simon F]

where is it leaking?
what does the pressure read when cold?
after bleeding the rads what pressure did you put the system up to?

 

[dexterulo]

Its been seen by engineer and he says its needs a new Pressure release vave and its a big job. Hes quoted 280 for a new PRV fitted.

My mother refilled it up to 2 bar by accident because the filling loop continued to fill after she closed off at 1 bar for a second or 2.

We are thinking of getting another opinion because its only started since the rads where bled. So we think it would have to be very coincidental for a part to go at the same time.

Would just like an honest opinion from a good plumber!

When cold the preassure gauge reads just above 0.

 

[SafeGasInstall]

where about ate you in uk ?

 

[ManchesterGas]

The ev needs re pressurising or replacing.

When there was air in the rads, it was using the rads for expansion, now there is no air and the ev needs charging/changing, the pressure goes up, past 3 bar, spits the excess water out of the prv and when it goes cold, the water contracts again, bringing the water level below the low limit and it needs water again, you need to fill up and it starts again.

What boiler is it?

If you fill up to 1.5 bar and don't use the heating or hot water, does it drop then as well (over a good 6-12 hours)? If so, you probobly have a leak too.

 

[SafeGasInstall]

is more to me like they over pressurised system prv let water out and can not reset ,but I agree with 500 on his/her scenario

 

[dexterulo]

The ev needs re pressurising or replacing.

When there was air in the rads, it was using the rads for expansion, now there is no air and the ev needs charging/changing, the pressure goes up, past 3 bar, spits the excess water out of the prv and when it goes cold, the water contracts again, bringing the water level below the low limit and it needs water again, you need to fill up and it starts again.

What boiler is it?

If you fill up to 1.5 bar and don't use the heating or hot water, does it drop then as well (over a good 6-12 hours)? If so, you probobly have a leak too.

This is exactly what is happening. Not sure what happens if we don't use hot water or heating over 6-12 hours. I haven't tried that yet.

What is an EV?

How much do you think this should cost to fix...a fair price?

 

[SafeGasInstall]

no one can give you a genuine guide price without been able to investigate the fault

 

[dexterulo]

How much would you charge to replace a PRV? on a glowworm combi then?

Mother has just said overnight everything is off. No heating or water. pressure just drops to just above 0.

 

[SafeGasInstall]

so you need it done straight away , must as well list your location and there is a good number of trusted plumbers here that can help you

 

[dexterulo]

No when boiler is switched off overnight. Boiler is giving heating and hot water. Just losing pressure and getting to high. We have heating.

 

[armourer]

PRV isn't a massive job but I would also be checking the expansion vessel charge / diaphragm.