In message , Roger Mills
writes
On 20/03/2018 21:37, Tim Lamb wrote:
In message , Tim Lamb
writes
Confused at Marford.
The plumbers flew in and fitted the new boiler, associated heating
manifold connections, diverter valve and coupled up the DHW header.
For some reason they appear to have fitted a pressure operated relief
valve directly across the tank coil!
When I queried the purpose there was some mumbling about it being
shown on the boilermate connection diagram. When I persisted they said
it gave a route for the water when the valve closed.
This is a W plan system using a Honeywell V4044C diverter valve. I
suppose there may be a short period as the valve transits from hot
water to heating when there is no flow. Even so, this diverter appears
to be in the wrong position.

Erratum! relief valve not diverter!

Any experience/thoughts?


Sounds like a by-pass valve. There may be some point in having one
between the pump outlet (before the diverter valve) and the boiler
return. But if it's after the diverter and directly across the coil it
will never do anything because the coil will always present a lower
resistance path than the by-pass valve.

Any chance of one or two photos?

Copper knitting? I'll try later.

--
Tim Lamb