High ....then Low pressure with Heatline compact

Hi All

I did have a trawl in the posts andsuspect this is a PV issue..
Is that Vessel or valve...or both?
I'm currently having with my Boiler. High Pressure.

Combination Boiler.
Heat Line Compact
Hot water is fine.
Started CH up for winter

Pressure , after 5 mins moves from 1bar to 3-4. and then off the gauge!
Bled the Rads. Some air but then bled water to reduce Pressure to 1-2b
Stays low then when i switch off. (no room stat) when i restart the pressure light comes on.won't start as pressure is below 1br,
Soi refill to 1-2 through loop. (Loop is closed ff tight after) then it sits at 1-2 for about 5 mins then climbs and climbs 2,3, off the scale.

Have repeated the above about 5 times trying t get a balancebut can't.

Any ideas please?

R

How old is the boiler? Sounds like you need the expansion vessel pumping back up, a new prv and the vessel hose/pipe checking for blockage.

See Boiler Pressure Problems in the FAQ section.

Thanks for the quick resonses.
Yes I've now had a better trawl and did find the "high pressure" posts.
Now.......
I have located the air intake valve (car type) (what a nightmare position!) I am a little confused what i am loking at.

On top of a valve type thing next to it is a red button/twist type that has on the brass neck "1/2" written. When i turned it(!) water was heard rushing through and when i went outside, it indeed had come out (Water) the expansion pipe. Also there is a little bead of water the top of the valve(car type)intake.

Alongside all this is a long silver rad type thing. 7x3 x1 inches .is that the vessel or is the vessel with the vale thing on it. Which to change either looks a complete access mare!

Should i just pump it up (air open on rad etc) and fingers crossed!

Whats the red button (above description) for?

Sorry for longpost
r

is it the s24/s30? yes it is a bit of a tight

if you see water coming out the valve on the expansion vessel then it could mean that the diaphragm inside has burst. if it does need to be replaced then the boiler needs to come off the wall to get to the expansion vessel .

just to try tp re-pressure the expansion vessel first

also it could be easyer to fit a externel expansion vessel to your system

I can't see the model number anywhere.

There is also a little corrsion underneath / around the valve....white dust etc , so it maybe this has been leaking(the valve )for sometime..or did i rip the diaghram to bits when turning the red swtch.

Shuld i just have a go at pumping it up and hope for the best/

Taking it off the wall is beyond a novice....isn't it?

Will his amount to £££££££££££££ to ge someone out. Boiler is (i've lived here 3 years ) about 6-7 years old

R