"Clive Summerfield" wrote:
It is actually the builder that states that the NHBC guarantee on the tank
was for two years. However, the workmanship should be guaranteed for up to
10 years under NHBC, the tank itself shouldn't have failed after only 3
years. Bottom line is that there are a number of options he can follow to
get this repaired without incurring further costs.

I suspect the workmanship on the tank installation is not
guaranteed for up to 10 years on the NHBC warranty.

The 10 year part of the NHBC warranty only warrants that the
house was built to building regs - *nothing* else. If this covers
the workmanship on installing a water tank, I'd be surprised.
The OP's friend *might* have got somewhere with the NHBC
warranty during the first two years, where slightly more is
covered and the builder is responsible for rectifying faults (rather
than insurance). Since the two years is up, that's irrelevant.

Bottom line is, there's no point in the OP's friend trying to
claim on the NHBC warranty, but as you say, there are a
number of other options open to them.

I would say the question comes down to: If the OP's friend
had had a water tank fitted three years ago and it had started
leaking, would they have any recourse? I would say they
ought to have some, as you might reasonably expect said
water tank installation to exist fault-free for at least five or
six years. I would suggest that trading standards would be
useful people to contact, but be wary that they might try to
fob the OP's friend off by saying it's an NHBC warranty
issue (which it almost certainly isn't).

Al

PS One of the only positive points about electrical work
coming under building control in the form of Part P is that
the electrical installation will now be covered by the ten
year part of the NHBC warranty, unless NHBC find some
cleer way of weaseling out of it.