Replacing expansion vessel on condensing boiler

[JDLDIY]

Hi there, I have a Worcester Bosch Greenstar R28HE System boiler, which according to my other half has sprung a leak from the expansion vessel. I'm thinking of getting the part and replacing it myself - is this a bad idea? If the vessel is split does that pint to a bigger problem or do they go regularly for some reason? Are there any more parts I neeed to purchase at the same time?

Why would a plastic tank like this spring a leak? Obviously I'll be checking the joints etc.

Many thanks for any help.

 

[doitall]

I doubt for one minute the expansion has sprung a leak, possibly the other half means the prv is discharging water, which points to a problem with the vessel.

Changing the vessel is not normally a diy job as it means taking the boiler off the wall, but without looking at the MI I don't know your boiler, so may be wrong.

The normal cost effective way is to fit a remote vessel, but if it really is leaking that is not an option.

 

[JDLDIY]

Thanks doitall. Well i'll just have to see later on....
If the prv (I take it that means pressure relief valve) is discharging the water, what could be wrong with the expansion vessel?

Thanks again

 

[kevplumb]

it needs recharging

 

[bengasman]

Why would a plastic tank like this spring a leak? Obviously I'll be checking the joints etc.

Plastic???

Never seen a plastic expansion vessel, are you sure you are talking about the right thing?

 

[JDLDIY]

OK, so now I've got home. The system had lost quite a bit of pressure - so I've filled it up to the mark on the pressure gauge. Could this have caused the vessel to become over pressured, and if so how is that?

Got it working again now and so far no leaks, I could see that it had been leaking from the valve on top of the plastic vessel as there were drip lines.

Obviously I've got a leak somewhere from a rad - will be looking for that.

Many thanks again, just trying to avoid yet anther large bill.

 

[kevplumb]

OK, so now I've got home. The system had lost quite a bit of pressure - so I've filled it up to the mark on the pressure gauge. Could this have caused the vessel to become over pressured, and if so how is that?

in short no

 

[kevplumb]

ang on this vessel thats been leaking

View media item 11231
like that only black

View media item 11246
or even

 

[plumskull]

[quote="doitall"

I doubt for one minute the expansion has sprung a leak, possibly the other half means the prv is discharging water, which points to a problem with the vessel.

No it doesn`t.

Changing the vessel is not normally a diy job as it means taking the boiler off the wall

No it doesn`t.

The normal cost effective way is to fit a remote vessel,

No it isn`t.

 

[kevindgas]

to clarify plumbskulls comments

1. expansion vessel is on left hand side of boiler
2. it is approx 8"x14"x3" in size and usually grey or red in colour
3. it can be changed easily without removing boiler from wall.

if the expansion vessel has failed I would be looking for the reason as this isn't a particularly old boiler and IMO, would indicate very poor system water.

if it as Kevplumb has shown then this is the Auto air vent and can be cleaned (turn off C/H valves and depressurise boiler first)

 

[plumskull]

Got it working again now and so far no leaks, I could see that it had been leaking from the valve on top of the plastic vessel as there were drip lines.

Faulty blow off.

 

[JDLDIY]

Hi there, yes it's a red vessel to the left of the boiler. The valve at the top is like the top picture.

Still isn't leaking any more since repressurising the system, will be keeping an eye on it, it's bound to do it again I suppose.

Many thanks, very grateful.

 

[kevplumb]

thats an auto air vent thats been leaking

 

[JDLDIY]

So what does the auto air vent do? Would you recommend replacing it, I'm tempted to just leave it and see what happens.

 

[kevplumb]

in simple terms its a float and a valve

air wont lift the float so it escapes

as soon as water enters it lifts the float and closes the valve

in theory anyway