Summer combi boiler pressure drop

[silver50]

Hi there’s a bit of history to losing pressure but things were better (and acceptable) for the last year or so. However just in the last month I’m losing more pressure. Lost 1bar in last 4/5 days.

No leaks in the CH system have been evident (there’s a house below me too..) but I know that doesn’t necessary mean it’s fine.

I think my gas engineer concluded it might be the boiler. Emphasis on might be. It’s old and needs changed now TBH.

This is really my question please. With no CH on at all and having this recent dropping in pressure does that lean towards more chance my pressure loss might well be in the boiler?

I’m on the cusp of going ahead with a boiler change anyway but it’s a bit of a depressing thought that I’ll still have a leak.

I know I might but I’m just interested to know views on this recent summer loss of pressure when there’s not been any heating on.

Thanks

 

[terryplumb]

The fact that your problem has recently become worse has nothing to do with the season of the year. You are losing pressure within the boiler ,or on the radiator/ pipework side. Your engineer should be able to establish which it is. If you isolate the flow and return valves at the boiler ,electrically isolate it , bring pressure up to 1.5 bar beforehand when rads are cold. Then leave it off overnight ,longer if you can. If pressure drops ,loss is within the boiler. If no loss ,and you then open the isolators and pressure then drops ,the loss is on the system side.

 

[silver50]

Thanks. Hmm yes that now jog's my memory. He didn't seem to want to shut off the valves (see pic) because he said that type always leak if you move them (suppose are quite old. 18 yrs approx).

Would you agree those are maybe best left alone..?

Think it'll have to be a suck it and see scenario with a new boiler. It's an old Vokera linea plus 32kw I have. To be fair it's still plodding along ok but it'd just not be worth fixing so a preventative change seems like a good plan.

 

[terryplumb]

If they haven't been used much in 18 years I wouldn't chance it now !! Nor would I spend money on it , rather go for a new boiler.

 

[jeff the gasman]

I take it the expansion vessel has been inflated and the pressure relief valve is not letting by. No leaks on gland nuts!

 

[silver50]

Hi thanks for the above replies

Yes I also now remember the expansion vessel being checked and recharged/pumped up, what ever gets done to it.

Not sure what you mean re gland valves but it was all looked over. The boiler was looked at regarding pressure dropping roughly 1.5 years ago. As I was saying earlier things seemed a lot better latterly so it’s a bit of a puzzle it getting worse.

A different gas engineer told me 3/4 years ago that the heat exchanger was cracked but the other one (more recently) said it looked sound.