Replacing a water/heating timer with DraytonLP722

[Riverstar]

I wish to replace a old water and heating timer with a Drayton LP722 the old timer has a wiring configuration of L&N (in) N (out) L1 (out) L2 (out) The Drayton configuration is N L 1 2 3 4 so I am wondering how I should wire it up?

 

[oilhead]

Use the cross reference chart in the LP722 packet. What timer are you replacing?

 

[JohnD]

have you got the installation instructions? Drayton (ACL/Invensys) produce a fold-out page that explains the wiring. You should be able to download it.

https://www.draytoncontrols.co.uk/products/time-controls/lifestyle/lp722

"documents"

https://www.draytoncontrols.co.uk/sites/default/files/LP722 (U.&I. Guide)_1.pdf

If you have an abnormal installation they may send you the instructions if you email them.

 

[stem]

You will need to determine what the existing wires represent. Is L1 Out, hot water and L2 Out heating? I don't know as you don't give the make or model of the existing timer. There should be a wiring diagram inside or on it somewhere that will tell you what they do.

Then it's a matter of moving the wires from the old timer to the Drayton LP722 terminals using the diagram below. You shouldn't need to use terminals 1 or 2

N&L are self explanatory then terminal (3) is hot water on and terminal (4) is heating on.

If you have an elderly system that has gravity circulation of hot water and pumped central heating, instead of control by motorised valves the the Drayton LP722 should be moved from the 'fully pumped' setting, to the 'gravity' setting.