Hi all

My present S Plan CH system has a pumped return rather than flow - is there
any reason why I should swap?
I am getting quotes for a replacement condensing boiler and intend to do
some re-piping at the same time. Does this have any impact on the answer to
the above question? ie pumped return OK with new style boilers?

The system currently suffers from pump-over which I would like to resolve.
As the pump is in the return to the boiler, the feed to the upstairs HW
cylinder continues past the cylinder to become the vent pipe. The motorised
valve connection to the cylinder is teed off this flow line, so does not
obstruct the clear vent. But the water make-up into the primary circuit
connects to the return from the cylinder coil. So, if the hot water
motorised valve closes, it effectively separates the vent from the water
make up (this I believe may be causing the pump over).
Is there any reason why I shouldn't move the water make up connection to the
other side of the HW valve? This would position it in the flow/vent line
close to the tee for the cylinder coil supply. If I do this, it would be
similar to a combined feed and vent arrangement, but with the feed entering
at HW cylinder level rather than at the header tank IYSWIM.

Hope this lot is clear

TIA

Phil