Replacing a HW/CH Controller Box

[stem]

It often happens that when cables are run that there is a spare core, or maybe in the past your system had a 3-Port valve instead of two 2-Port valves in which case the extra wire would have been used. However as the system is working OK now, it isn't needed so nothing to worry about. Don't make any new connections.

also a loop wire from L to 5. There is no terminal 5 on the Drayton, so do I just ignore this one?

Ignore the loop from L to 5, it's not required by the Drayton. I explained why in an earlier post.

You will see they are virtually the same, with the exception of terminal 5 of the EP which is missing from the Drayton. However if you look carefully you will see that this connection is made internally inside the Drayton, so it doesn't have a terminal 5.

Also nothing in the left-hand neutral strip.

The neutral strip is provided for the original installer to use if they wish to use it as a junction box. As there are only 2 neutral wires with your installation they fit nicely in the N terminal, so no need to use the other strip.

You are fortunate. Your EP has just been wired up as a programmer and the junction box facility hasn't been used. If it had, you could have ended up with three times the number of wires connected in there.


So:

Blue and black wires in EP N go to Drayton (N)
Two reds in EP L go to Drayton (L) [loose the red link to 5]
Red in EP 3 goes to Drayton (3) Hot Water on
Yellow in EP 4 goes to Drayton (4) Heating on

 

[KennyPowers]

Ok thanks, I'll give a go over Christmas