"Roger Mills" wrote in message
...


SNIP


Seconded. And your reply was very good Roger.


Thank you, kind sir!

I *hope* I got it right, but I was a bit worried after writing it when I
delved a bit deeper into the installation manual. That describes the plug
M7 as "Low voltage connector (heat request)" - but I was recommending
feeding mains back to Pin 3 on it. However, unless *all* the external kit
(motorised valves - including 3-port valve for Y-Plan, stats, etc.) shown
in the diagrams work on low voltage, M7 *must* have mains on it.

Can anyone clarify?


Not an independent view I know, but I got in from work at 4.30, fed the cats
and downloaded
http://vokera.co.uk/wp-content/uploads/2009/04/pinnacle_installation_and_servicing_instructions.p df

On diagram 8.1 Fig 31 I saw the S plan. A small deviation from the "standard
Y plan". But it is the same as I have fitted to a combi with an S plan
(don't ask Drivel).

Then I saw fig 32A. QED.

The final proof was fig 34. Control of time clock and room thermostat
rated at 230V ac.

All I had to write was seconded. You had done all the work:-)


But a query about the bypass valve. Should an automatic bypass open
up as some of the TRVs close down in the system and help keep the
pump from running under excess load?


Possibly. An even better option would be a smart pump - but since this is
a system boiler, presumably with an internal pump, the user probably
doesn't get to specify the pump.

My point really was that, in the absense of zone valves, there will[1]
always be an open flow path to allow pump over-run to operate without
needing a bypass valve.

[1] providing not all rads have TRVs


The bypass is a
http://www.myson.co.uk/products/1207_1625_ENU_HTML.htm
according to the OPs previous posts.

Point [1] taken into account.

As for removing the hot water then the mind boggles. But it is still a free
country and the OP can do that if he wants.

Cheers

Adam