Combi Boiler Unusual Pressure Problem

[Mickcd]

Hi, hope someone can help. I have a vokera linea combination boiler and it has been losing pressure at quite a fast rate. I searched for a leaky pipe/fitting to no avail and then eventually found that there was a leak from the heated towel rail in the bathroom. I normally check that the pressure is at 1.25 bar when cold. I isolated the towel rail by closing off both valves each side of the towel rail and this has stopped the flow going through ( as expected). However, now when I turn on the central heating, the pressure rises rapidly to 3.5 - 4 bar when hot ( usually sits around 2-2.5). When cold it drops to 1, sometimes under 1 bar. I have been over the last few days bleeding the radiators thinking that in isolating the towel rail air has managed to get trapped in the system. I bleed the radiators to reduce the pressure initially, however in doing so when the heating is off and cold the pressure is too low. Do I need to just keep doing this until it levels out? Or remove the towel rail altogether, drain the system and re-fill the whole system? Or is there another explanation? Please advise, thank you

 

[dcawkwell]

Expansion vessel in the boiler needs to be repressurised.

 

[1983]

The problem is probably with your expansion vessel. It likely just needs charged but it could also be faulty or it's connecting pipe blocked. A service on the boiler should include recharging this if required.

 

[Mickcd]

Thanks for that, is this something I can do myself? Is this the technique with the bicycle pump? If so, have you any idea where I might find the valve on this particular system. Thanks

 

[Dan Robinson]

I love it when people think they have an unusual/rare/odd/urgent/strange problem that they've searched the forum for and found nothing.

So here we go -gonna ask anyway



Not taking the pish Mick - just a general observation based on a lot of recent posts .

 

[Mickcd]

Not sure what you mean dan, but the problem I have is unusual to me as I have never come across this before. I am not a plumbing engineer (clearly) but consider myself as a handy enough person to accomplish most tasks around the home. I have been able to understand and carry out obvious/initial checks etc... and try to eliminate them before I ask for guidance from elsewhere, which is what I am doing now

 

[Dan Robinson]

Search the forum for "unusual" problems - even try the list at the bottom of your screen and see how "usual" your problem actually is.

Don't worry - I appreciate its not your fault and this isn't a personal attack.




Just wish people would read the FAQs and search a little before asking questions.

 

[Mickcd]

Appreciate that Dan, thanks for the advice. I think I gave up on searching this evening as I have been checking round for leaks again this evening, trying to find the original manual, downloaded a PDF of the manual, searched generally over the internet (finding lots of posts/videos/etc.... not quite relative to my problem), until I thought, I need to find a forum to get my own question out there. I am under no illusion that this has probably been asked before but I am at a point where I just need a direct answer/suggestion(s). So forgive me if that comes across as lazy, it really isn't the first thing I have done to try and sort my problem out ....now I am going to bed and confront this again tomorrow evening

 

[Dan Robinson]

This forums search engine is pants.

But at least your problem is here and it is solvable.

Good luck!

 

[Agile]

Its actually a very common problem.

Perhaps the cause of 2-3 posts here every week!

Tony