"Roger Mills" wrote in
:


I haven't used a bypass, as I have no TRV on my hall rad where the
thermostat is, also there's a bathroom rad/towel rail.

If that's really bad, perhaps someone would tell me!


It's bad if your boiler needs pump over-run. With an S-Plan system
*both* valves close when both demands are satisfied - and if the
boiler needs the pump to keeo running for a bit after it shuts down,
the water hasn't got anywhere to go!

Good point - it doesn't apply to me at present, but if I change the boiler;
of course, I think I'd get someone in to do that; too much gas fitting!

I'm a bit concerned about the gate valve on the return pipe

I have a gate valve on the cylinder return at the moment, which was
installed to balance the CH and HW circuits so that when both are
running at the same time the HW doesn't hog all the flow.

See reply to Christian

My concerns about my modified arrangement are these:
1. Currently, the cylinder flow pipe only goes up as high as the top
entry point on the coil. In the new scheme, it will go higher and come
down again. I don't *think* that matters, but would welcome comments.

My flow pipe goes higher, so I have an air bleed at the top. It's only been
used when refilling.

FWIW, I'm also planning to
fit a Grundfoss Alpha variable flow pump. Again, comments will be
welcomed!

I use an Alpha, but I'm not convinced it was a good move; it seems a bit
noisy and vicious, the old pump seemed to work extremely well; top speed
for blowing out airlocks, bottom speed nice and quiet and worked well.

YMMV

mike