Switchmaster 400 packed up, Convert to Drayton LP112?

[jrwilshire2003]

Hi all,
I currently have a Switchmaster 400 which has given up the ghost on the central heating side as it no longer fires the boiler up or the pump. Thinking of getting a Drayton LP112 as a replacement but was wonder if its easy to change to. Have looked on the instruction sheet for the LP112 but cannot find where to wire the thermostat into? Any ideas? Apart from that it looks pretty simple to change over. Thanks all!!

 

[D_Hailsham]

Have looked on the instruction sheet for the LP112 but cannot find where to wire the thermostat into?

The thermostat connects to the CH ON terminal - no 4.

 

[45yearsagasman]

I hope you have proved that its the programmer at fault and not a motorised valve.