"news" wrote in message
...
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

In days of yore, the hot water cylinder was often heated by a separate
gravity/convection circuit that was uncontrolled.

If it is to be part of the pumped system, either it will have to have either
some sort of manual control valve to balance the system
OR more usually
it has a separate circuit controlled by a motorised valve/s
(thermostatically controlled) so that it can be shut off or the entire
boiler output goes to quickly heat the water.
This is a lot more useful and efficient.

If the new tank has no means of balancing/restricting the primary water
flow, you will likely find that most of the primary water goes through the
coil and almost none through the radiators.