Plumbing help - Pressure Loss

The_One · 16 Dec 2007 at 20:40

Our combi boiler over the last few weeks has started losing pressure.

Normally its set at just over 1 bar but after 3 or 4 days it drops gradually to about half a bar so i then add more water to get the pressure back up.

Apart from the pressure loss it seems ok, heating is working well and taps become hot like they usually do.

What could be causing the pressure loss? Could it be losing pressure when taps are on for a decent amount of time?

Cheers

schnipps · 16 Dec 2007 at 20:46

Likely a leak somewhere mate, could be anywhere in the system, just a few drops on one pont over a few weeks will drop the pressure. Had the same problem in my old flat, we just topped it up once every 4 weeks. Depends if you are moving on soon or not, if you are going to be there for the next few years + you need to get a plumber out.

Trill · 16 Dec 2007 at 20:52

Bleed all radiators.

The_One · 16 Dec 2007 at 21:04

Cant see any leaks.

We had new bathroom fitted a number of months ago, all piping is boxed in with whole bathroom tiled

Will try bleeding the radiators

schoey · 16 Dec 2007 at 21:05

i had this on mine and it turned out to be a knackered pressure vessel (behind the boiler)

The_One · 16 Dec 2007 at 21:11

hopefully its smething like that and not a leak as we havent noticed anything.
surely pressure loss is related to the central heating and not running water as i thought its only the rads that are pressurised??

ANDARIAL · 16 Dec 2007 at 21:14

aye my guess is pressure vessel too

Check to see if there is any water escaping via the overflow/relief pipe(put a cup or summat under it over night etc)

mikeh501 · 16 Dec 2007 at 22:11

Had a similar problem and checked the same things as the posts above. I'm not sure of the technical term but the one way valve inside the flexi pipe which allows you to fill your system with water wasn't one way anymore. I would fill it up, and after a few weeks it would go back to zero. The actual water in the heating system was going back into the mains water for the house.

Obviously that was on an old combi. The current ones have the water fill bit inside them now.

Edit: It was this bit. Specifically the bit on the left.

JBuk · 16 Dec 2007 at 22:20

we just had our combi condemned

no running hot water now and maybe not until the new year

afraser2k · 16 Dec 2007 at 22:58

My central heating has gone on the blink today, no hot water coming through the system though the mains supply is fine for pressure etc so hopefully something easy enough to fix. I got the HomeCare 300 cover from British Gas so the engineer is out tomorrow morning so I'm glad I got it now even if it's the first time I've used it in about two years.

My old central heating system was condemned (old flat boiler tank thing) and took about three days for the new system to be put in. Ended up costing me about £3000 and that was with a discount.

Typical that it had to happen on a Sunday though.

JBuk · 16 Dec 2007 at 23:10

afraser2k said:
. I got the HomeCare 300 cover from British Gas so the engineer is out tomorrow morning

.

we got a british gas engineer on a no fix no fee call out, was him who condemned the boiler, he then disconnected it

if only we left it another few weeks until after christmas....

lookitsjonno · 16 Dec 2007 at 23:17

problems here too, have to keep pumping more water into it every 2 weeks using the thingy in the pic above. need to get a plumber round i think, don't want it going totally biting the dust over xmas :mad: