Combi Boiler pressure high

riko_uk

Hi Guys

First time poster, long time reader

We have just switched out heating on for the first time this autumn and seem to have a problem with the pressure. We have a Worcester 24cdi (I think, it says British gas on the front but I'm sure its the 24 cdi) and the pressure when cold is just over 1 bar. usually with the heating on this goes up by about 0.5 bar but yesterday I noticed that after it had been on for 50 minutes it was over 2.5! I switched it off and once it cooled down it was back to the usual 1 bar. I didn't notice this high pressure the first couple of days we used the heating (though I can't say I looked at the gauge) however I did bleed a radiator yesterday. I wonder if removing the air has somehow caused this?

Just to be sure we had a fault, I put the heating back on last night and sure enough the pressure crept up to over 2 bar before I switched it off again.

Any advice would be appreciated.

cheers!

Graham

Canucklehead

Hi

Expansion vessel needs checking.

GSR.

moneysaver

We had the same problem with ours, as above expansion vessel needs pumped up with air.



Moneysaver

keystone

It could be it needs repressurising or it could be that the diaphragm is knackered in which case just pumping it up won't help one iota.

Cheers

gas4you

If you press the valve on the expansion vessel and water comes out, then you need a new one.

Avint

Boiler pressure too low
Hi, We have an opposite problem, Our Boiler pressure is 0.5 bar. Boiler is about 8 years old and from what I can gather previous house owner didn't service it. So when we called in a specialist he didn't even manage to undo the main valve that needs cleaning apart from saving up for a new boiler are there any other options at all?

latecomer

get another plumber in to have a look. just becasuse its not been serviced doesn't mean it needs replaced.

silkyuk9

riko_uk wrote: »

Hi Guys

First time poster, long time reader

We have just switched out heating on for the first time this autumn and seem to have a problem with the pressure. We have a Worcester 24cdi (I think, it says British gas on the front but I'm sure its the 24 cdi) and the pressure when cold is just over 1 bar. usually with the heating on this goes up by about 0.5 bar but yesterday I noticed that after it had been on for 50 minutes it was over 2.5! I switched it off and once it cooled down it was back to the usual 1 bar. I didn't notice this high pressure the first couple of days we used the heating (though I can't say I looked at the gauge) however I did bleed a radiator yesterday. I wonder if removing the air has somehow caused this?

Just to be sure we had a fault, I put the heating back on last night and sure enough the pressure crept up to over 2 bar before I switched it off again.

Any advice would be appreciated.

cheers!

Graham

we have a worcester also and its regually servcied by BG ive asked this question before, if the bar is up to one its ok, but if it goes too high there is a safety release valave you should see it outside your house, if the pressure is too high it releases itself, so water should come out of the release pipe outside.

dont worry about it just get it checked out.

macman

Avint wrote: »

Boiler pressure too low
Hi, We have an opposite problem, Our Boiler pressure is 0.5 bar. Boiler is about 8 years old and from what I can gather previous house owner didn't service it. So when we called in a specialist he didn't even manage to undo the main valve that needs cleaning apart from saving up for a new boiler are there any other options at all?

Make and model would help.
If it's a combi, have you topped up the pressure via the filling loop under the boiler?
What 'specialist' was this? Was he a GSR installer? If he didn't even check the filing loop then he cannot have been a competent or qualified RGI.
Is the pressure 0.5 when cold or when running?

Avint

Hi
Our boiler is Worcester Bosch 24CDI. When I noticed that pressure was too low it was running just for hot water and as I didnt know what to do I just tuurned the thermostat down so the heating wouldnt come on as programmed by timer. Now the pressure is 0.4 but I didnt use hot water since last night. Guy who came to service it is a certified installer for Worcester. The valve he didnt manage to clean was impossible to undo as he tried with chiesel and hammer but was afraid to go on as said all hammering may damage other parts. My husband normally knows how to top up pressure but he is away for couple days so really dont know what to do. Thank you

macman

You should still be able to run the CH, if the pressure is too low the boiler should cut out anyway. Suggest you call your OH and ask him to run through the top up procedure, it's really very simple and takes a couple of minutes or less.