Told boiler needs a new expansion vessel along with pressure relief valve - how much should this be?

[ShaunCorbs]

I have been running my system like this for the past 4 years, no problem. Changing boiler this year though as the existing one is 15 years old.

You sure your system isn't open vented?

 

[dan_the_plumber]

you do realise the air will eventually move / get dispersed

 

[dan_the_plumber]

you do realise the air will eventually move / get dispersed

 

[Martyn2]

You sure your system isn't open vented?

Positive!

 

[ShaunCorbs]

Positive!

That's a yes correct?

If so that's why you haven't had a problem

 

[Harvest Fields]

As far as a new expansion vessel goes, there is an alternative. You can drain the system and after refilling, partially bleed one radiator, preferably in a room you don't use much. This will act as an expansion vessel. As the pressure relief valve is a purely mechanical device I suggest yo dismantle it, give it a good clean and retest.

This used to be used as a short term fix to get people through the weekend on a Friday evening. Not a long term fix

 

[Sarah Wykes]

I'd have thought it pretty tight, tho' there's a chance (not sure of the size of vessel you need.)

What's under the microwave space - is there a kitchen base unit? If so, I'd have thought it could go in there.

Could you post a further-back picture to show what's around the boiler?

Sorry for the delay but here are some more pictures

 

[Sarah Wykes]

Sorry if someone has already said but how has the bloke come to the conclusion you need a new vessel? Leaking water? Cant be recharged? Pressure always dropping?

The pressure is always dropping

 

[Sarah Wykes]

Just gone through your first post you mention the plumber who was doing a Gas Safety check is this a Rented property ? are you the tenant ? or the owner ?

I am the owner, the first time renting the house and the tenant should be moving in in a couple of weeks

 

[sammathias]

The pressure is always dropping

Has he tried recharging the vessel? Renewed prv? Still dropping? Potential central heating pipework leak?

 

[DevsAd]

Assuming that the plumber has done the obvious stuff and checked that the boiler's exp vessel is knackered, then your options remain as before, Sarah.

1) New boiler - circa £2k
2) New boiler vessel + PRV - £350 (with the associated risk of disturbing the boiler, but looking at the photo the flue shouldn't be an issue).
3) Fit an external exp vessel and replace PRV - I dunno, £200-ish?

An external vessel could be fitted on that adjacent wall - very ugly indeed - or possibly in a nearby room (where do these pipes through the ceiling go to?)

Anyhoo, your own plumber is the guy who's going to carry out whichever of these jobs you decide on, so discuss the 3 options with him 🙂