Low Pressure Problem

[bazsal]

Boiler is Vokera Excell 80 SP

I had it serviced a month or two back, as was having problems with the pressure going down and having to top it up. There are no noticable leeks round radiators, and we have been decorating some of the other areas of the house and found no damp or anything anywhere.

The guy who serviced it (corgi reg) advised there was a slight water mark round something (not sure what part it was now) but it wasn't uncommon and /or an issue and just to top it up.

Have been doing that. It goes from 1-1.5 Bar to preety much zero within a week/10 days. Recently noticed that when I top it up, water is coming out of the pipe external to the house for if the system is overfilled (forget what they call it!). Could it be that the pressure gauge is inaccurate and I am actually topping up when there is no need? Any other suggestions?

 

[ArtfulBodger]

Your pressure relief valve is letting by and will need replacing. This is usually caused by it operating in the past when the pressure exceeds 3 bar and contaminants in the system preventing the valve from reseating correctly.

 

[oilman]

The service guy should have checked the expansion vessel for correct air pressure. There's a BS spec to cover it. Search the forum foer details oct/nov 2003 there's loads of information.

 

[bazsal]

Are these fairly easy things to put right? Presumably if this valve is the problem its a case of replacing it? What likely costs am I looking at?

 

[bazsal]

The guys been tonight and pumped up the expansion vessell, which he thinks should cure the problem.

He suggested replacing it was a big job as the boiler had to come off. Is this right?

 

[kevplumb]

it is if you want to replace like for like you can fit a second one on the system tho

 

[bazsal]

thanks

how much would I be looking at it costing to replace it?