Central Heating Programmer

[GordyBeet1]

Danfoss FP715Si programmer, have been doing some tiling and eased programmer away from wall to slip tiles at the back, and a blue wire has come out and I dont know where from, there is the main blue wire from mains but this is a slightly thinner wire there is only one position it seems it can go as there is no wire in position 4 of six, I have lost all the display on the front and nothing is working at all, can anyone help please.

 

[flameport]

Unless you can find out what the other end of the wire connects to, there is little hope.

Almost certainly it does NOT go in the empty terminal, since on most heating systems, that terminal (heating off) is not used.

 

[flyingsparks]

Is there a wire on the neutral terminal labelled 'n' ? If not that's where it goes would explain why nothing works now (no display etc)!

 

[ericmark]

It would be nice if wires came with one colour for each function like with a car green with red trace right hand indicator etc. But that is not the case. We would hope blue is neutral but it could so easy be line.

This is a typical wiring diagram

and the wires out of the motorised valve likely do follow the colour code. But that pink wire likely will not be pink.

There are plans Y, S etc. If you can work out which plan you are using then that's first step.

 

[GordyBeet1]

Thank you for your reply's, I have since checked the fuse to the system and found it blown have replaced 3amp fuse and all now lights up, but have not tested all the functions but boiler heating and water seems to come on and work, is it possible that the wire is not used, and same as you say should I trace it back and see what it is connected to if anything, the blue neutral thicker wire is connected so not anything to do with that. thanks for your comments all, kind regards Gordon.

 

[ericmark]

With central heating 2,3,4, and 5 core cables are often required. Most electricians will have 2 and 3 core cables but after that then doubling up on cables is normal. If that is the case then likely some cores are unused.