Leaking expansion valve -> new boiler??

Sorry - just to clarify "it" means the whole boiler, not just the expansion valve.

And if it really *is* necessary, does have any case against Gloworm here?

In article , Lobster writes

What's an expansion valve :-? Ok, it'll be the expansion vessel but it suggests there's already a Chinese whisper thing going on.

On a more helpful note, built in expansion vessels tend to be located behind all the working gubbins and some are reputed to be a bitch to change, requiring the boiler casing to be removed from the wall if it's a difficult install position. The boiler bloke may have said, "I'll need to take it off the wall to change that and that will cost XXX so you may as well swap the boiler out at the same time". Either way I would resist the push to change a 4yo boiler without some pretty strong justification from the boiler jock.

Read the SealedCH FAQ. What is/was the symptom.

A good repair including flushing out the whole system shouldn't be more than a few hundred.

It is true that some boilers are not worth repairing (and shouldn't have been purchased in the first place because of that). However a GW is a mid range unit and should go somewhat longer than 4 years.

I think he might mean a failed expansion vessel (sub £50, but might take up to a couple of hundred to fit). Or a failed pressure relief valve (about £10 and a minimum charge job).

OK, have a few more details now. It's a combi boiler; in fact the model is an Ideal Response 120 not a Gloworm.

Dripping from the pipe outside (pressure relief valve?) which causes the CH system to depressurise and require topping up via the filling loop; (so yes, it appears the expansion vessel is shot).

I wonder is it feasible to fit an external expansion vessel (alongside the knackered one if that's too awkward to get at?)

So does it sound as unreasonable as it appears, to condemn a 4-year old boiler for this?

I've also ascertained that the guy who's told him it needs replacing is the same engineer who fitted the boiler in the first place. I've already recommended he gets at least a second opinion, fast!!

David

It could be just the pressure relief valve leaking, either needing cleaning or a good blow off by operating the knob on it.

If not then has the pre-charge been checked in the expansion vessel? a tyre pressure guage will check that on the schraeder valve on the PV. it should be somewhere in the vicinity of 0.7bar with the water side de-pressureised. If not try re-pressurising (with foot pump or similar- requires ingenuity) and then topup the water. If it again loses pre-charge (or if the PV is full of water on the dry side) it may require replacement of the PV, perhaps withan external extra one) BES seem to do them at a reasonable price (last time I looked).

See above.

OK. The pressure releif valve is letting by, probably indicating a failed expansion vessel. Pumping them up usually only works for a few weeks/months.

It may be cheaper and easier to fit an new vessel on the CH return pipe.

Alasa, this boiler tends to have a rather dire stock fault which is failure of the main heatXer. If this has happened then you might as well replace the whole thing. If this has not yet happened then it's worth making the repairs even if the boiler only has a couple of years left to live.