Help with wiring Drayton timeswitch LP711

[GaryWright]

Hi
Could somebody please help me with a wiring problem? I am replacing an old dial timeswitch with a Drayton LP711. I made a note of how the old timer was wired which was L and N from switched fused supply, L and N from boiler into the same L and N as supply with also white cable into terminal 2. Lastly room thermostat was L into terminal 1 and N into terminal 2 with the white cable. The old timer stated that 1 and 2 were the load, 3 and 4 were unused. I replicated this wiring on the Drayton LP711 so have L and N from supply and boiler, L from stat in 1(com) and N from stat and white cable from boiler in 2. I noted from the instructions that terminal 1 has no supply so looped in a cable from the L.
The outcome is the boiler turns on and off when turning the stat up or down, but it stays on when the timer turns off!! Do I need to move the cables from 2 to 3? Or do I need to split these, with one in 2 and one in 3? If so, what way round?

Please help.

 

[twgas]

Tell us more about the old timer, boiler and system; like makes and models etc

 

[GaryWright]

Boiler is Alpha InTec 28x combi condenser and old timer was Switchmaster 300.

 

[GaryWright]

I have now wired it with the following

L N and Earth from fused supply
L N and Earth and white cable (I assume switched live) in terminal 3
Looped in Live from L to 1 (com)
L in 1 (com) and N in 2 and Earth from thermostat

The timer now works and turns on/off as programmed, but the thermostat is now not working and the heating stays on even when the stat is turned to zero!! Am I missing something simple?? Please help

 

[lauriehurman]

Hi Gary

Yes
You said that the output of the timer was terminal 1 which went to the thermostat and the output of the stat went to 2 which was then the switched input to the boiler.
And then you bypassed the timer by linking terminal 1 to permanent live.

Remove that link and it sounds like you may be alright.

Laurie

 

[GaryWright]

Hi Laurie

I tried removing the looped in live link but this didn't work. I think I have the boiler wired in correctly but not the thermostat (Drayton combi-stat), where do the L and N of the stat go?

Gary

 

[lauriehurman]

Hi Gary

Just found the wiring diagram on the Drayton website "draytoncontrols.co.uk/documentation"

As you say;
link L to 1
output to stat in 3
return from stat into 4
switched live to boiler into 4

try that
Laurie

 

[D_Hailsham]

L and N from switched fused supply, L and N from boiler into the same L and N as supply

That's OK

with also white cable into terminal 2. Lastly room thermostat was L into terminal 1 and N into terminal 2 with the white cable.

So there is a white wire from the boiler to T2 and a brown/blue (or red/black) cable from the stat to T1 and T2?

Is T4 on the old timer connected to anything, e.g a link to L?

 

[GaryWright]

Thanks for replies, sorry it's taken a while (have to work as well!!)

Laurie, will try your way tomorrow and see how it goes

D Hailsham, yes on the old timer T4 was looped into the L