On 2020-10-20 14:24:21 +0000, Andy Bennet said:

On 20/10/2020 15:22, Andy Bennet wrote:
On 20/10/2020 13:17, Graeme wrote:
In message 2020101823510528942-nospam@nospamcom, John Smith
writes

Be careful wiring in the new head as if the board is anything like ours
it's rather small and easy to forget what goes where and to
accidentally set another wire loose.

I have taken multiple photos and drawn a wiring diagram, just in case :-)

What I'm not sure about is the two black wires which go into the valve,
from the cable to the boiler.* One black wire is connected to an orange
wire, the other to a grey wire.* Not sure whether it matters which
black wire is connected to orange and which to grey.


The orange and grey leads go to a NC microswitch. The switch closes
when the valve fully arrives at the open position. It does not matter
which way round you wire those leads but i'm sure somewhere ther must
be a convention. The blue and brown leads power the little motor and
are turned on/off by your thermostat. (for completeness the
yellow/green lead is the earth!)

I re-read the above just after I hit 'send'. Err the microswitch is NO not NC!
soz

It's well worth getting familar with the wiring so one understands what
you are doing.

This is a typical S plan system with two 2-port valves like we have
although we don't have a room stat only a cylinder stat and programmer.

https://www.flameport.com/electric/c...ng_diagram.gif

Video also:

https://www.flameport.com/electric/c...ing_S_plan.cs4