Replacing 2 port valve - Motor on/Motor off to Spring Return

[nwgas]

Hows it going? I'm new to this forum, thought I'd double check something with you guys.

I'm a gas engineer (not too good with the electrics). Got a faulty C/H 2 port valve. The existing one is an old sunvic motor on/motor off valve, but where I work, we only fit the Drayton spring return valves.

As you need a permanent live for the Drayton valve (grey wire), do you just go in the programmer wiring and move the wire from C/H off to Live to get the permanent live?

 

[matt1e]

I would have thought no need as presumably your momo also switches the call for heat anyway so you just wont need the ch off connection

more info on how your existing actuator is wired would be better

Matt

 

[nwgas]

Cheers for the reply.

The mains voltage goes into the clock rather than the junction box and then the clock diverts the voltage as req'd. The room stat goes through the 2 port I'm assuming as you only hear the click if the valve is connected.

So you just take the c/h off wire out of the equation and you just need to get a permanent live from somewhere to go to the grey wire of the spring return valve?

 

[matt1e]

usually the room stat will power open the valve
the valves internal micro switch will close when the valve is open and this in turn is used to fire the boiler

whether you need to pick up a permanent live for your new valve depends on how the original valve is wired

Matt