Worcester Bosch exp vessel and prv replacement quote

[Guynextdoor]

Hi,
Just wanted to check something on a quote I've had if that's OK
Worcester Bosch greenstar junior 25kw combi
Fitted in 2015 and symptom is that when the central heating is turned on, pressure starts low then rises to over 2 bar and water trickles out of the prv pipe outside. Then eventually as the system cools, pressure drops to less than 1 bar

I had an engineer round to take a look and he said expansion vessel needs replacement
As vessel is at the back, the boiler will need to come off the wall which makes it a bigger job and its probably a good idea to change the prv at the same time. Sounds reasonable to me, however

The quote is around £800 and includes draining the central heating system.
My question is does the entire system need to be drained to do this ? Can't my heating system be isolated ?
Thanks

 

[sjmac]

Get another quote, seems expensive to me. Even if you did need to drain the system, that's hardly a big job

 

[kidgreen61]

Can't he fit an external exp vess?
PRV replacement is a fiddle, but easily done in an hour.
£800 is taking the pizz.

 

[Madrab]

Does the PRV stop dripping when the pressure drops? I presume he has tried to re-pressurise the EV?

Remote EV would be the choice, if there is a space for one and would be much much cheaper.

 

[CBW]

Could be a blocked hose too. As suggested get another quote, Worcester fixed price repair is a damn sight cheaper.

 

[mattylad]

Here is a video showing how it is done:

(Note: I am not suggesting you do it yourself).

As the others have said, get another quote, esp the WB one.
Also try the re pressurization.
It is recommended (in the video comments) to change the prv at the same time if the boiler is off the wall.

Some more info on the expansion vessel itself.
ALso suggesting how it can be easier to remove dependent upon your flu.