central heating wiring centre

[Mattodl]

Hi all. Recently moved home and the wiring is a mess. The central heating only operates if the cylinder thermostat is low enough to send a call for heat. The system also has a satisfied which if I wire correctly sends the boiler into fault mode as obviously it is receiving 2 different messages.

I believe the biggest issue which I can not figure out is where the switch live for the boiler is? The pump has its own power feed however also runs with the secondary wire along side the blue wire (believe to be water)
I will add some pictures and see if anybody can easily solve this puzzle.

I also believe the cylinder stat needs a permanent live on the comms port. However how do I locate the comms (permanent live in the wiring centre) and switched live from the boiler.
Thanks

 

[terryplumb]

Need more details of your system components , programmer, Ch stat, cylinder stat . Motorised valve 3 port?

 

[Mattodl]

Hive hot water and heating programmer and thermostat however old wiring is still in place and linked in hallway.

A Drayton hts3 cylinder stat.

A corgi 3 port valve.

a grundfos ups2 water pump

thanks terry.

 

[terryplumb]

The switched live to the boiler would/ should be in the terminal with the orange conductor from the 3 port valve, together with the wire from the cylinder stat that calls for heat. The cylinder stat would only have a live feed from the programmer when the programmer is set to hot water ON.

 

[Mattodl]

I always believe the far right sleeved yellow was the switched live as the brown wire from the pump sits with it. However the secondary wire next to the blue (hot water call) powers the pump, however does not directly run to it.

 

[Mattodl]

The black wire which is comm sits within the wire with the orange. And the call for heat sits with the call for heat wire from the controller. The only way I receive heat is when the cylinder stat calls for heat which in turn fires the heating. The biggest issue I’m having is locating the switched live.

as the secondary wire with the blue powering the pump indirectly some how has confused me

 

[terryplumb]

When boiler turns off ,does pump continue to run for a while ?
The cylinder stats com terminal wire should go into a terminal block with the programmers hot water ON wire.
Have you looked at the boilers terminal connections to establish what colour conductor is in its SL terminal ?
Unfortunately there is no " standard" for what colour wires are used in a lot of the wiring ,with the exception of the 3 port conductors which are industry standard ,and of course earth conductors.

 

[Mattodl]

I’m not sure I’m yet to check. The comm wire currently sits with the orange off the port and runs into a red. Do I presume this is the switch live?
I’m just confused as to why a wire that does not run directly to the pump somehow powers it indirectly once seated with the hot water on wire from the programmer.

 

[terryplumb]

This wire that doesn't run directly to the pump ,where does it run to ? The boiler ?
The boiler would preferably control the pump ,in order to make the pump run on after the boiler closes down ,enabling the heat within the boiler to be disbursed.
If the pump is wired any other way ,the pump would stop as soon as the boiler does.

 

[Mattodl]

I can’t tell as it dives into the flooring. It’s strange as the 3 wires from the pump (standard 3 core) non of them have any interaction with the wire powering the pump. The live is the brown at the far right.

 

[terryplumb]

Sorry ,not with you . The brown wire going to the pump is powered by the yellow ( with red sleeve) that's in the same terminal block. If the pump runs on after boiler closes down then the yellow/ red is coming from the boiler .

 

[Mattodl]

Correct however the pump also powers off the normal red wire sat next to the hot water wire (blue sleeved red). Which does not directly run to the pump so I am unsure how it is powering it.

 

[terryplumb]

How so ? The cable going to the pump you said was 3 core ? The brown is in terminal with yellow ( sleeved red) the neutral in the neutral terminal and the earth in with the earth's.????

 

[Mattodl]

That’s my point somehow that red wire must power the yellow wire under the flooring or down at the programmer. This has blew my brains

 

[terryplumb]

Sorry ,I don't know what your talking about. The pump has a live neutral and earth ,the live supply to the pump is from the yellow wire( sleeved red) which comes from the boiler. That yellow ( red sleeve) conductor is within an outer sheath ( not showing clearly in your pic), with other coloured conductors. What other coloured conductors are in there ,and where do they connect in the terminal strip. I expect there is a red ,a blue ,green/ yellow and the yellow with red sleeve .