Boiler Pressure

[screamer]

I bled the radiators the other day, then topped up the boiler pressure, i turned off the valve at the mark on the gauge, but it ended up going to just under the 2bar
after being used for a few days i checked the pressure again when the boiler was off, the pressure was down to 1bar and when the boiler is on its up to 2bar
tried to check to see if anything was coming out of the relief valve pipework but can't see anything due to the weather just now

Could this be the expansion vessel knackering up?

Worchester Greenstar 24i

 

[Harry Bloomfield]

tried to check to see if anything was coming out of the relief valve pipework but can't see anything due to the weather just now

Put a plastic bag over the end, fixed tightly in place with an elastic band. Bag will collect and show any water which comes out.

 

[screamer]

Put a plastic bag over the end, fixed tightly in place with an elastic band. Bag will collect and show any water which comes out.

topped it up again today and ran the heating, an hour or two later i seen outside water coming out of the relief valve drain.
New expansion vessel needed?

Also, would this cause the house to feel colder than normal?
I know we're on colder weather just now, but it does seem a lot colder in the house lately

 

[terryplumb]

Does pressure ever rise above 2 bar when central heating has been on for a few hours ?
Water loss from PRV will not make your house colder ,unless the boiler stops working !

 

[screamer]

Just checked as the heating isn't long on, it's sitting a fraction below 2 1/2 bar

 

[terryplumb]

The EV may just need to be recharged ,but the prv shouldn't really lift below 3 bar .
Your system pressure when the boiler is cold doesn't usually need to be above 1 bar. If you are having to top up in the morning ,what does it drop to ?

 

[screamer]

it was sitting about the 1 bar, i topped it up to the mark in the gauge, think it's about 1.5 bar, but when turning off the valve, it usually stops the pressure straight away, but the pressure keeps rising gradually to near the 2 bar, you don't hear any more water going through the top up valve when it's turned off

 

[terryplumb]

If you top up to 2 bar when cold ,it's no surprise that the prv has lifted ,that is just too high.

 

[screamer]

ok, any idea on why the pressure would increase after i've top upped and it still rises and the valve isn't passing?

 

[terryplumb]

Lazy valve ,not closing immediately ,gauge not very responsive.