Navigating my central heating circuits and fitting 3rd Gen Nest

Hi all,

First time I wired it - given that it was all a bit ad-hoc, I just switched the wires around but must not have wired the pump properly, so the boiler started and went a little crazy!

I guess the clue is here. The boiler overheated
 
I don’t think so, the earth wires from the mains, boiler and thermostat were all wired in to one earth cable. When I first had a go with the Programmer wiring, I think I wired in the boiler without the pump and it may have just overheated the PCB or something.
 
I guess the clue is here. The boiler overheated
Yep! I have emergency breakdown cover, so best bet may be to wire it all back up and call them out for the boiler fault. Despite breaking the boiler, at least I can have some minor confidence that my (final) wiring was right!...
 
Their bound to spot something, but has to be worth a go.

They will probably recommend a new boiler at £4K when you can get one for £2K.
They could say, you can't get the parts anymore. So its not covered.

But, try and get the hotwater circuit activating the pump to be sure its wired correctly
 
Yep! I have emergency breakdown cover, so best bet may be to wire it all back up and call them out for the boiler fault. Despite breaking the boiler, at least I can have some minor confidence that my (final) wiring was right!...

That would be fraud. It was not a breakdown, it was damaged by an unqualified person fiddling with something he did not understand.

You also said earlier that you were unable to wire it back to origional.
 
That would be fraud. It was not a breakdown, it was damaged by an unqualified person fiddling with something he did not understand.

You also said earlier that you were unable to wire it back to origional.
I’ll have to read the fine print and see. It’s fully wired into the Nest system now.
 
My brother-in-law decided he wanted boiler cover for my father-in-law, I objected but was over ridden. So he looks around and selects Home Serve. He told me what a great deal it was, only £125 I think, can't remember exact figure, bargain. However they arrived and said the system needed flushing first, we paid a firm to flush it, they put in inhibitor/cleaner which should clean out anything not taken out with flush, two months latter Home Serve again say it needs flushing, how they know I don't know, all they did was take a water sample, that may show there is copper, iron or other minerals in the water, but them being present, does not mean there is likely to be a blockage. I have washed my hands of it, clearly they don't want to take on an old boiler and will use any excuse not to take it on, if they continue to use cleaning agents next thing will be a leak. Already spent two days waiting for Home Serve to attend and take over the job, far more man hours then they are ever likely to save, and while they were faffing about my father-in-law has died and the house sold.

Having seen how they take money off the dead, they would not it seems simply cancel contract which they have not as yet accepted, they just say it will be transferred to new owners. To my mind it is a fraud, they want money for nothing, so if you can get them to fix it good on you.
 
It is called probate, where they can charge the estate, they have not delivered goods or service to date, but have been paid, it seems clear it will never be refunded, neither will they do any work on the central heating system, and since house is now sold, they will get away with it. I think we should be able to charge them for our time when my brother-in-law sat in his car 9:00 am to 3:00 pm when they finally told him they were not coming plus a round trip of 180 miles.

I also sat there to let them in to service the boiler, he took a water sample then went away doing no actual work. Clearly since it has been flushed we can simple run water through the system until clear and add yet more inhibitor, but why should I for a house which is sold? If a pipe was blocked then OK I can see they want it cleared before they take it over, but it has been fitted with two motorised valves and a new pump plus extra radiator this year, clearly nothing blocked.
 
I would want one of two options, either the service and maintenance contract for the year, or return the money already paid cancelling contract, but it seems they want us to do work not required to keep the system running or they will keep money and do nothing. To my mind either small claims court to get money refunded or write it off, and make sure never have anything to do with Home Serve again. Not up to me, but seems latter is more likely. Had my father-in-law been still alive then spending money to ensure he always had a warm house was a good investment, however when the service engineer is 3 weeks late, and then all he does is take a water sample and does not service the boiler, I wonder if it was to fail would they actually repair it?

OK we are I suppose lucky, we can afford to write off £125, others are not so lucky, and being asked for £250 to repair system or forfeit the £125 is clearly nothing short of blackmail.

However considering how they behave, if anyone can work a fast one on them, good on them, would be nice to see them getting a little of their own medicine. OK two wrongs don't make a right, but I will lose no sleep over it.
 
View attachment 148886 I just tried switching the cylinder stat 1 & 2 wires (although I actually realised I had them as @EFLImpudence had suggested) - so this was now:

7 - valve grey cylinder 2
8 - valve orange, cylinder 1, pump and boiler L

I said it was this way around before as (maybe I’m being an idiot but) that’s what the Nest wiring diagram (previous post) seems to suggest, but having relooked through the Honeywell diagrams (above) they state as @EFLImpudence does, which is how I had originally wired them.



The power came on after changing the fuse, tried HW on first and nothing happened, then I tried heating and the fuse blew again. I’m assuming the cylinder stat is wired incorrectly this way and therefore the hot water remains off as the boiler didn’t come on (and the circuit didn’t blow on just HW).

It sounded like the valve clicked over when I turned the heating on, so I’m once again assuming that it’s either the boiler or pump that’s shorting the circuit?
So do you think the circuit shown in this pic relates to the boiler requirements?
 
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