Logic Combi ESP1 35 always showing demand for Central heating

[John.g]

Yes, that seems correct.

 

[theboyroberts]

I can confirm that the black wire is dead when there is no call for central heating and the goes live at 240V when the call for central heating is activated via the thermostats.

I'm assuming that I'm going to need some form of switch which is off when there's no power and switches on when there is power?

 

[John.g]

If the link is linking a permanent live to a boiler switched live, then if it is removed and if the 4th terminal from left is live and the third from left is dead that the black wire from the stats goes in here (third from left) but this is just my reading of it and may be incorrect so someone else on here may advise you.

 

[theboyroberts]

The wire that I was referring to being being live is the one in the attached picture at the boiler end. So, I'm confident that the wires in the airing cupboard are correct and there's a live feed which activates when the thermostats trigger the call for central heating.

Is the solution to put a relay switch in the boiler with the following wiring?

Please forgive my diagram!

 

[John.g]

What is that red link "linking??.

 

[theboyroberts]

The red linking came as part of the boiler and is referenced in the instructions. See the picture attached.

 

[Deleted member 120897]

So, I'm confident that the wires in the airing cupboard are correct

I wouldn’t be so sure, as I’ve seen a defect, which I pointed out earlier.

Is the solution to put a relay switch in the boiler with the following wiring?

No relay is require, and if you do it as per your diagram, your likely to kill your boilers pcb, and pop the fuse. Probably best getting a gas safe registered engineer in competent in wiring heating systems as well. That way, the case seal to your boiler can be checked (not recommended that a non gas safe person removes) and it’ll be fixed properly. For the time being, you can continue to use the heating, just by adjusting the temperature at your boiler.

 

[theboyroberts]

First up, thanks for everyone's help so far; its really appreciated.

Undertrained - I agree that I should get someone in, and most likely will. However, one thing which I'm struggling to understand is how the demand for central heating could every work without a relay with the way in which it is currently wired?

As I see it (total layman, so I'm more than likely wrong) the room stat linking wire will need to be removed and replaced with some form of switch which controls the demand for central heating based on external factors such as a thermostat. Without a switch/relay how will the demand for central heating ever be anything other than always on?

 

[John.g]

Good advice. Purely from a interest point of view I see it as the roomstats via the timer/programmer are powered from a permanent live, the roomstat outs are combined (orange wires, as per S plan) as one (switched) live and I would have thought would normally be connected in terminal 3 (link removed) and supply the switched live to the boiler for CH control.

 

[ShaunCorbs]

It’s as easy as removing the red link and installing the black wire in where the right hand terminal where the red link one eg closest to the live terminal

 

[John.g]

Terminal (from left) 3 Shaun if terminal 4 is live with link removed?? (post 15).

 

[Deleted member 120897]

It’s as easy as removing the red link and installing the black wire in where the right hand terminal where the red link one eg closest to the live terminal

EditEd, I see it now 😩

 

[theboyroberts]

Just like the attached ShaunCorbs?

 

[theboyroberts]

John.G - not sure if you've noticed, but there's blue sleeves on the grey wires.

 

[Deleted member 120897]

John.G - not sure if you've noticed, but there's blue sleeves on the grey wires.

That just denotes the grey wires are being used as neutral wires.
My bad, just noticed the grey from your zone valves are connected to lives, the neutrals are connected to grey sleeved wires acting as neutrals. So yes, just connect up as Shaun has said, just the black wire to the terminal closest to the incoming live - NO LINKS!

 

[Deleted member 123817]

If the link is just removed and the stats are still switching the supply then thiseans that they are fed from elsewhere and the black wire should be inserted in terminal 3, period.??

 

[Deleted member 123817]

What number terminal is this please, from the left.

 

[theboyroberts]

I believe i understand this now 🙂

The black wire which enters to the bottom of the Room STAT/Timer block link is carrying power which is carried over through the link into the red wire leaving the bottom and activates the demand for central heating. Hence the boiler firing constantly.

By removing the link and placing the black wire in the 4th position (counting from the earth as number 1) as soon as the thermostats activate, power travels down the black wire and the demand for central heating fires the boiler.

Is my understanding correct?

 

[Basher]

What number terminal is this please, from the left.

I agree with your post #36
From the technical sheet, diagram C, the boiler requires switched mains on terminal 3 from the left - ie the left hand connection of the red link, which will be removed.
So the black wire goes there, and nothing goes in the next one, according to diagram C.

 

[Basher]

I believe i understand this now 🙂

The black wire which enters to the bottom of the Room STAT/Timer block link is carrying power which is carried over through the link into the red wire leaving the bottom and activates the demand for central heating. Hence the boiler firing constantly.

By removing the link and placing the black wire in the 4th position (counting from the earth as number 1) as soon as the thermostats activate, power travels down the black wire and the demand for central heating fires the boiler.

Is my understanding correct?

No that is not consistent with what Diagram C shows. Surely the power needs to be fed into the next terminal along - the 5th position as you are counting?