Rewire Problem

[Ben Lewis]

Good Morning,

I currently have a Honeywell ST699 heating and hot water programmer which I am looking to replace with the Drayton MiGenie.

However I'm having a few issues with it not working and since the swap over cannot get any hot water or central heating (severely in the dog house at home now!)

Could someone please assist with putting this right as I'm currently stumped.

Thanks in advance

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[dansk]

looks like you have introduced another wire. your old set up only had one wire for the ch on.

 

[Ben Lewis]

looks like you have introduced another wire. your old set up only had one wire for the ch on.

Yes your right it appears I assumed terminal 4 should be a neutral ! Any ideas on how to wire this up to my new programmer ?

 

[Lucien Nunes]

That was not a neutral, it was a switched line coloured blue! I agree it is unlikely to be W-plan. To completely clarify, it would be necessary to understand what type of motorised valve(s) you have and how they are wired. Nonetheless, if you are 100% confident about which wire came from which terminal in the old unit, it is possible simply to transfer them to the correct terminals in the new. The difference between the two is that the common contact of the CH and HW relays is internally connected to Line in the MiGenie, whereas there were separate terminals (5 & 8) in the Honeywell that had to be linked with wires in the terminals. And of course the terminal numbers are different, they map as follows:
Honeywell (H) -> MiGenie (M)
H3 -> M4
H4 -> M2
H5 n/a
H6 -> M3
H7 -> M1
H8 n/a
If you are not sure which came from where, then you have a much bigger challenge as they will have to be traced out electrically.

 

[Ben Lewis]

That was not a neutral, it was a switched line coloured blue! I agree it is unlikely to be W-plan. To completely clarify, it would be necessary to understand what type of motorised valve(s) you have and how they are wired. Nonetheless, if you are 100% confident about which wire came from which terminal in the old unit, it is possible simply to transfer them to the correct terminals in the new. The difference between the two is that the common contact of the CH and HW relays is internally connected to Line in the MiGenie, whereas there were separate terminals (5 & 8) in the Honeywell that had to be linked with wires in the terminals. And of course the terminal numbers are different, they map as follows:
Honeywell (H) -> MiGenie (M)
H3 -> M4
H4 -> M2
H5 n/a
H6 -> M3
H7 -> M1
H8 n/a
If you are not sure which came from where, then you have a much bigger challenge as they will have to be traced out electrically.

Thank you very much, I do however have nothing wired in H4 so can't put it in M2 unless you meant I need to link live in to M2 ?

 

[Lucien Nunes]

If there was no wire in H4 (CH off) then that strongly suggests that the system is a conventional Y-Plan with a mid-position 3-port valve. Correspondingly, there should be no wire in M2. If that blue was just floating about before, it should be made electrically safe as the situation at its other end isn't known.

 

[Midwest]

Would it not be best for the OP to show what system he has installed first, before advice is given how to wire it up?

 

[Lucien Nunes]

It would, however given that the common terminals of the old controller were linked to line, it should be a straight swap. As I mentioned, if there is any doubt about the identity of the conductors, it's a different ball game, and it would probably be wise to call in an expert.

 

[Ben Lewis]

I am confident now it's a Y-Plan system as I have a Y-Plan 3 position diverter valve. I also know all the wiring colours for the pump and immersion thermostat so maybe better off requiring it from the start. Thanks again for your help.

 

[Ben Lewis]

Ok turns out the spare blue was in fact a neutral so now all back up and running again.

Thanks again for everyone who assisted I really do appreciate it and am very grateful !!

 

[telectrix]

nice to see a result. OP 1 - CH 0.

 

[Ben Lewis]

nice to see a result. OP 1 - CH 0.

Yes mate and being honest this MiGenie is spot on, can't recommend it enough and the integration with home automation is next (I do like a challenge!)

 

[telectrix]

me too.love a challenge. every morning i challenge my legs to get out of my pit.so far .i'm winning, but the legs are gaining ground. i hate being old. a teenage tearaway trapped in a 70 year old body., still could be worse.