Gloworm Ultracom 30CXI

[satts]

Hello all,

My combi boiler has just been fixed by an independent firm (was leaking internally from a pipe which had to be replaced) and is now all working fine apart from when heating is off pressure 1.5bar when house is up to temperature >20 degrees the pressure is 2.5bar and the condensate pipe is dripping into the drain outside. Before I ring them and get charged more I would like to be armed with a bit more info. Do I need to be concerned and is there a problem or is this normal? They did say that the bladder was flat and had to be pumped up?? Many thanks!

 

[Dan Robinson]

Expansion vessel need checking and either recharging or replacing.

 

[satts]

Replaced the expansion vessel but pressure still keeps going up every few days and I have to bleed some out the radiators to get the pressure down to 1.5 bar as it goes up to 2.0 bar with the heating on.

 

[terryplumb]

Cold system pressure around 1 bar should be fine. Its normal for pressure to increase when system is hot ,as water expands. As long as it does not get much above 2 bar that's fine. You don't need to drain water out JUST because it gets to 2 bar. Is that what you are doing ?

 

[satts]

Well I have to to keep the pressure from going up to much. The cold pressure rises by about 0.2 bar every couple of days then rises about 0.5 with the heating on. It seems as though the system pressure is creeping up somehow overnight when the heating is off. Other than that everything is working fine - perhaps i am looking for problems....

 

[terryplumb]

If you have had the expansion vessel fitted professionally ,then the filling loop may be letting by ,can you disconnect it ? That would rule out that possibility.or you may have a pin hole in the plate HEX. If you stopped draining pressure ,what would be the result ?

 

[satts]

No I am a Mechanical Engingeer not a qualified Gas Engineer. I fitted the expansion vessel myself (quite an easy job and I would never touch anything on the gas side) as I had to order by a boiler parts comapny as British Gas will not change the expansion vessel as it is not covered under the contract. I have signed up to having a new boiler fitted by British Gas in April however. It had the PHE replaced a couple of years ago due to black crale blockage. Also this boiler has an inbuilt filling loop so rather reluctant to disconnect it. Thanks your assistance.

 

[terryplumb]

If you stopped reducing pressure ,does it just keep going up till it gets to the point where the prv opens at around 3 bar ?

 

[satts]

No I havent let get above 2.5 bar. The highest It went up to was 2.4 bar then I decided to bleed some out of the bathroom rad (easiest so I can monitor the pressure). Since then I made sure it is 1.5 - 2.0 bar when I check it in the morning before the heating comes on so it never goes above 2.5 bar. Should I just leave it to bottom out then and not interfer any further? Thanks.

 

[terryplumb]

When CH is cold pressure to ,1 bar. Then leave it alone ,but just monitor pressure . you may not even have a problem. If it works there's no need to fix it.

 

[satts]

Yep will do. Although I did reduce to 1.2 bar last week (cold) then heating on 3.00PM then off at 11.00PM. Next morning pressure 1.5 bar ( cold). Somewhere 0.3 bar gain. Will post back with more data. Thanks.

 

[satts]

Just some feed back - there are 2 grey taps on the ultracom cxi for the inbuilt filling loop. The plastic taps were rounded off and not closing the valve fully so removed the taps and cycled the valves a couple of times with a large slotted screwdriver. The pressure has been steady since. I am going to get an external filling loop fitted so I am not interferring with the boiler anymore if ever i need to add a radiator / flush out in the future. Thanks.