"Set Square" wrote in
:


PROS
* Less individual components to accommodate and install - since it
doesn't need zone valves or a by-pass loop - (but it *does* need the
anti-gravity valves)
* Failure of one half of the pump would still enable the other circuit
to operate (but there would be no pump-over-run if the HW pump failed)

CONS
* The pump and control centre are proprietary, and cannot be replaced
by generic components in the way that S-Plan components can
* You have to have precisely two circuits as opposed to S-Plan, which
can (in its S-Plan-Plus form) accommodate unlimited circuits by the
addition of more zone valves - enabling (for example) separate control
of upstairs and downstairs radiators

You pays your money . . .

I think you're right - last winter my 3port valve failed, and after advice
from hereabouts I was able to replace it pronto, even though it needed the
wet bit replacing.

I was shopping today in a shed, and loadsa pumps and valves were available
- I could replace them as soon as the shops opened.

Ta

mike