Logic Combi ESP1 35 always showing demand for Central heating

[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?

 

[theboyroberts]

Got it 🙂

 

[Basher]

Got it 🙂

But I'm not buying a new boiler if it's wrong 🤪

 

[theboyroberts]

Just heading out folks - really appreciate the help.

I'll make the change when I get back at about 7:30pm and will report back.

Thanks again!

 

[Basher]

This assumes that all the wiring centre power is coming from the same supply circuit as the boiler.
That is the proper and most likely arrangement.

But if you get issues with an rcd tripping (not MCB) then that would point to them being on different circuits from the consumer unit, which would need to be corrected.

 

[theboyroberts]

They are on the same circuit - checked this when I flipped the RCD during testing last night.

Will report back later folks 🙂

 

[ShaunCorbs]

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?

Edit correct

 

[Deleted member 123817]

To be sure to be sure, remove the link and check for power at terminal 4 (from left)) if 230V there and 0V at termina 3 then black wire goes to terminal 3 .

 

[ShaunCorbs]

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

Sorry just seen instructions yep

 

[ShaunCorbs]

Just like the attached ShaunCorbs?

Without the red link linking live to room stat

 

[theboyroberts]

Sorted!

All working as expected 😊

Really can’t say thanks enough for all of your help - really amazing bunch of folks here on the forum.

Chuffed to bits!