what are you on about ??? it is a Combi boiler, the pump is internally controlled by the boilers PCB
Nest Thermostat 'E', not turning EcoTec Pro off, house like a sauna!
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As I have said the numbers don't match and @picasso pointed out seems I found wrong set of instructions, the pump is clearly controlled by the boiler, but that does not mean it has to be built into the boiler, but really it does not matter, the fact remains flex leaves the boiler, and clearly any wiring in and out of boiler would need to be of a type a stuffing gland can seal on, but the cable to programmer is triple and earth flat cable, so some where there must be a junction box, or it seems heating people call them wiring centres.
It would seem it has never worked as expected, but no one can hope to fault find when we have not been shown the wiring centre.
It would seem it has never worked as expected, but no one can hope to fault find when we have not been shown the wiring centre.
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Sorry, I thought id already posted these images. As you can see from the electrical tape on the neutral cable it looks like the previous owners had issues at some point.
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Sorry this
is what I mean as a wiring centre, in this case too many wires to fit in the Nest heat link so the junction box was fitted below it, I suspect some where you also have a wiring centre or junction box which is where the flex changed to flat cable, it is hard to seal on flat cable, so since the boiler is sealed and hopefully the seal tested after it is disturbed, some where the round cable changes to flat cable which you can see at the other devices.
Although the junction box/wiring centre shown is surface designed for central heating wiring, often they are socket boxes with blanking plates and a strip of connector block inside.
I know I also have a hidden junction with my central heating, in main house I have flat triple and earth red, yellow, blue, and when it arrives in the flat it is brown, black, grey so that rang alarm bells, on testing found one core was open circuit, running a new cable was going to be hard, so I had to find a way to work with two cores, and since there was clearly a fault want low current and voltage on those two cores, that is why I fitted Nest, I could control DHW and CH plus power the unit with 2 wires.
But until your junction box/wiring centre is found only way to work out how to wire is a long piece of wire and some device to "bell out" each wire. Normally we would use a multi-meter, however the name "bell out" comes from using a bell and battery to do the job, in many ways it works better than the multi-meter, but there is no magic cure, either you need to physically trace or test wires.
Although the junction box/wiring centre shown is surface designed for central heating wiring, often they are socket boxes with blanking plates and a strip of connector block inside.
I know I also have a hidden junction with my central heating, in main house I have flat triple and earth red, yellow, blue, and when it arrives in the flat it is brown, black, grey so that rang alarm bells, on testing found one core was open circuit, running a new cable was going to be hard, so I had to find a way to work with two cores, and since there was clearly a fault want low current and voltage on those two cores, that is why I fitted Nest, I could control DHW and CH plus power the unit with 2 wires.
But until your junction box/wiring centre is found only way to work out how to wire is a long piece of wire and some device to "bell out" each wire. Normally we would use a multi-meter, however the name "bell out" comes from using a bell and battery to do the job, in many ways it works better than the multi-meter, but there is no magic cure, either you need to physically trace or test wires.
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Ive looked everywhere for something like this but to no avail. Thanks for everyones help, it looks like I'll have to get a professional in.
Really couldnt be simpler, just rip out all the existing wiring and wire from scratch, 20 min job at most
Indeed. L N & E, which is already there, reroute the grey and black wires in 3 and 4 to the Nest-e. Remove the rest.
Don't worry about the wiring photo posted by ericmark. That system is nothing like yours, don't let it confuse you.
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Indeed. L N & E, which is already there, reroute the grey and black wires in 3 and 4 to the Nest-e. Remove the rest.
Don't worry about the wiring photo posted by ericmark. That system is nothing like yours, don't let it confuse you.
My nest E is now wired up as you described but once the call for heat is made the fuse in the boilers isolation switch blows. Any ideas? Its rating is 3amps and now I have no fuses left!
A nest E does not have a L N or earth it is a battery powered switch, the two cables are just that , a switch
If so, that is the correct way, so doesn't explain why fuses are blowing. So, either get a pro in as has been suggested, or try posting a couple of photos of the wiring connections at the Nest-e Heatlink and the boiler which might help.
Please stop posting that meaningless drawing, it doesn't help at all. Much of the important information is missing, and the programmer and the wiring to it should have all gone now anyway.
You should now only have 5 wires connected. The end of each wire being in a terminal on its own. The first 3 wires listed provide the 230V supply to the boiler and an earth connection.
Wire 1) Neutral from the 3A fused connection unit to the boiler N
Wire 2) Live from the 3A fused connection unit to the boiler L
Wire 3) Earth from the 3A fused connection unit to the boiler E
Wire 4) From the boiler '3' to Nest-e 'C'
Wire 5) From the boiler '4' to Nest-e 'NO'
And that's it. Nothing else should be connected.
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I posted the drawing once then replied with an edited version. It shows exactly whats in the images I also uploaded, including the heat link and boiler wiring which youve now asked for, it's all there.
A heating engineer came yesterday, said the boiler is fine and the issue is with the wiring. A nest pro came today and needs a second opinion as he's not sure what has gone wrong.
Definitely not as simple as has been suggested then. Thanks to everyone who had a go, cheers.
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Haha no, I managed it exactly as described. Also the nest pro couldnt get it working so maybe all he needed was a diagram. Thanks for your contribution.
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