Valves on a combi volt free

[grandfortune]

Hi all,

got a combi boiler with volt free switching for the central heating all working fine, I put a conservatory up and put underfloor heating in , I asked the plumber to put a value on the UFH pipe and the CH Pipe so I could control them separately , from a salas wireless programmable stat, so basically a s plan. I've come to wire it but having problem as the combi is volt free and I can't see how to open the valves without putting 230v to the boiler sw. Any ideas?
Cheers
grand

 

[stuartcourt]

what boiler as 99% have a 230v as well

 

[guest119]

Wont the valves be opened by the stats controller and the paralleled micro switches signal the boiler with its own go signal of whatever voltage?

 

[Redvanman]

Wire it up as if its a standard 2 port system. You will need a 240v supply thru your stat to open the valve and the stat terminals on the boiler should go thro the valves switch, which would be volt free. It would be the same for both valves.

 

[grandfortune]

what boiler as 99% have a 230v as well

It's an old jaguar boiler only volt free I'm afraid

 

[Spark1979]

Wire the 240volt side to work the motor side of the valve, feed this from your wireless stat control box then wire the volt free contacts of the boiler onto grey and orange of the valve

 

[grandfortune]

But when the valve opens doesn't it send 230 down the orange?

 

[Sharpend]

Can you not put it through a relay?

 

[onions1066]

But when the valve opens doesn't it send 230 down the orange?

I've done a lot of heating systems and you do have a bit of an awkward one there. Where is the valve in relation to the boiler? Close by?

 

[Redvanman]

I've done a lot of heating systems and you do have a bit of an awkward one there. Where is the valve in relation to the boiler? Close by?

Guys this is quite simple. The volt free contacts aren't in the boiler but in the external controls. There's a voltage of some sort coming out of the boiler hence the link you have to remove when fitting the external control.
wire the motor of the valve through a 240v supply via the room stat, blue neutral grey being switched feed from stat.
the grey wire in the valve connects to one of the external control connections in the boiler and the other connection is connected to the orange. This means that the volt fee contacts are in the valve across the switch. They are volt free when no voltage is connected to them but the boiler sends a voltage out of possibly 24v.
the second valve would be exactly the same connections and you can double up the orange and grey cables of both valves as this doesn't affect the switching of the valves independently
i hope this helps, you could draw the wiring out first to follow the switching and then you will probably have the light bulb moment good luck