A friend of mine has just had a (leaking) 25 year old HW tank replaced -
standard vented HW system gas heated by a secondary coil.

The house is just like mine and on the output of the secondary heating
coil there was a tap like body - neither hers or mine has ever had a
handle and I assume that it is the equivalent of the lock-shield valve
on the rads. It is designed (I assume) to stop the HW tank hogging all
the heat when both HW tank and rads are both demanding heat - but once
set during installation it can be forgotten (in just the same way that
the lock-shields are forgotten).

Anyway as part of the new tank installation this tap has been removed
and not replaced with anything. Is this normal for modern installations
or has there been some sort of drop off?

We wont find out how balanced the system is until much later in the year
and if its wrong I think it would be better to get the installers back
sooner rather than later.

Thanks for any advice

--
Chris