Expansion Vessel

[Swell1]

Hi, our Worcester greenstar 24i has an issue with the expansion vessel (its round at the back), it drips out the overflow and needs filling up alot.

A plumber suggested I press the tyre pressure valve and if water comes out it's a faulty vessel but ours let out a little air, no water, I pumped up to .75bar but it's still dripping.

Does this still suggest a replacement EV? Anything else I could try or is it simply getting the EV replaced.

Thanks

 

[CountryFan]

I think you’re getting the terminology mixed up. The pressure relief valve is likely the one dripping out of an “overflow”. Did you keep a drain cock open when you pumped it back up?

 

[terryplumb]

You are likely to not have followed the correct procedure when recharging the EV.

 

[Swell1]

I think you’re getting the terminology mixed up. The pressure relief valve is likely the one dripping out of an “overflow”. Did you keep a drain cock open when you pumped it back up?

Hi, thank you, he said simply to press the valve on the expansion vessel, if no water squirts out then pump it up to see if that solved the issue, no mention of drain cock, I assume this is needed when pumping up? Thank you

 

[terryplumb]

You need to de pressurise the system ,leave a drain cock open ( direct to a bucket or connect a hosepipe to a drain) and then pump up the EV.

 

[Johntheo5]

Also, when you precharge that air end to 0.75/1.0bar, refill it then to 1.3/1.5bar (cold), this then gives a nice little water reserve of ~ 2 litres without any frequent top ups required.

 

[richardmm]

hi i have the same problem the prv pipe is dripping from the outside and a local repairman has quoted me to replace the expansion vessel is there any way i can rule out first????

 

[CountryFan]

hi i have the same problem the prv pipe is dripping from the outside and a local repairman has quoted me to replace the expansion vessel is there any way i can rule out first????

Ask him or another engineer to pump it up, as this is often all that's needed. PRV likely needs replacing too.

 

[Swell1]

hi i have the same problem the prv pipe is dripping from the outside and a local repairman has quoted me to replace the expansion vessel is there any way i can rule out first????

Hi, if you press the tyre valve on the EV, does water come out as I was told this means the EV is faulty apparently, if just air then it could simply need pumping up, drain the boiler and pump up, I did this but still lost pressure, I then replaced the schrader value (from a bike shop), cost a few pounds and now holds pressure fine thankfully.

 

[richardmm]

Thank you!

 

[xd400]

hi i have the same problem the prv pipe is dripping from the outside and a local repairman has quoted me to replace the expansion vessel is there any way i can rule out first????

When you're running the heating does pressure go close to 3 bar?

Water coming out of the valve is not necessarily indicative of a failed expansion tank. Lots of water will come out just from condensed water, IME, they just needed re-pressurising.

 

[oilhead]

The difference between a dribble of condensation water and the flow of primary water from a failed expansion vessel is very noticeable.

 

[richardmm]

When you're running the heating does pressure go close to 3 bar?

Water coming out of the valve is not necessarily indicative of a failed expansion tank. Lots of water will come out just from condensed water, IME, they just needed re-pressurising.

it increases around to 2.8 bar but will get a technician in