Vaillant boiler

inacrisis

Hi all,

Have just had an annual boiler service and it was mentioned the expansion vessel needs replacing, cost approx £300. The engineer showed me why by pressing the small button and water leaked out.

Cause I have zero trust in any tradesperson (my dad is a retired builder and does everything for us except gas) I have done a bit of research and all the youtube vids on boiler servicing I have seen all show water coming out of this thing....They then say it needs to be drained and then recharged?? They also say that they have never come across one that needs replacing. Our heating has been working fine and never had to top up the water due to low pressure.

Anyone knowledgable on these, know if this just needs a recharge or actually replacing?

Thanks

markin

Its basically a balloon in a water tank, if water comes out its done

If you have room, an external expansion vessel seem to be the cheapest option i think.


https://www.youtube.com/watch?v=m1repkd1HHc

inacrisis

Thanks Markin,

Is this something that can be repaired DIY? or does it still need to be a gas engineer?

Also there seems to be varying prices for these....

I cant figure out if this thing costs £30 or £220?

£30
https://www.unventedcomponentseurope.com/vaillant-ecotec-expansion-vessel-181051-all-models.html

£180
https://www.plumbase.co.uk/vai181051-expansion-vessel-10000221-3528437


£80

https://www.akgas.co.uk/vaillant-expansion-vessels/vaillant-181051-ecotec-expansion-vessel-detail

markin

You need to be a gas engineer to take the cover off the boiler.



How old is it, is it still in the guaranty? It may only be valid if its been serviced every year.

5-year guarantee as standard, with 7 to 10 years available when you book a Vaillant Advance installer

https://www.vaillant.co.uk/homeowners/products/ecotec-plus-combi-832.html



You could phone around for a price now you know the problem, if it is £30, £300 to fit it seems a lot. Is he a Vaillant installer?

inacrisis

Thanks,

we have only lived here a year and don't have any kind of service manual, unfortunately.

Looking online, you dont need to take the boiler apart to do the external expansion vessel, it's just a matter of adding it to the existing pipe work next to the boiler.

THanks

southcoastrgi

He can't tell it needs replacing by pressing the valve, it needs repressuring to 0.75 bar, I very much doubt it's knackered

markin

If Water comes out the air valve the diaphragm has failed, so yes you can tell.

southcoastrgi

markin wrote: »

If Water comes out the air valve the diaphragm has failed, so yes you can tell.

No you can't because it could be condensation build up, the way to tell is pump it up & see if it holds pressure