Google Nest E installation - boiler not powering on

[WildWolf]

I've just installed a Nest E in place of our old thermostat and it doesn't appear to be working correctly. The Nest E and the Heat Link both communicate with each other fine but when the power is switched on at the mains, the boiler doesn't power up.

I've attached a photo of the old thermostat and the Nest E wiring.

The old thermostat is an EPH RF1A-OT and the boiler is a Worcester Bosch Greenstar 4000.

I do have limited knowledge but having followed the guidance I believe everything seems correct (though guidance wasn't brilliant).

Have I wired it correctly?

Would really appreciate any advice. Thanks.

 

[ianmcd]

you have wired the nest E correctly, check the 3 Amp fuse in the spur, but most likely you have tripped a breaker in the consumer unit when wiring it, they are extremely sensitive, or do you actually mean that the boiler IS powered up and just not switching the heating on when asked ?

 

[WildWolf]

you have wired the nest E correctly, check the 3 Amp fuse in the spur, but most likely you have tripped a breaker in the consumer unit when wiring it, they are extremely sensitive, or do you actually mean that the boiler IS powered up and just not switching the heating on when asked ?

Thanks for the reply Ian, really appreciate it. I did think this was correctly wired.

I've checked the CU and it's fine (no trip). I'll check the spur now and I'll also reconnect the old thermostat to check it's working with that before continuing.

Regarding the power, the boiler isn't powering up at all post installation of the Nest.

 

[ianmcd]

Regarding the power, the boiler isn't powering up at all post installation of the Nest.

the nest doesnt power the boiler, it is simply a switch, you have interrupted the permanent live somewhere, if the trip on the consumer unit is identified , drop it completely to off the reset back to on, some have a duel setting and if you touched the Earth wire it drops out but doesnt always look like it has, if none of that works show a pic of how the nest is wired at the boiler end

 

[WildWolf]

the nest doesnt power the boiler, it is simply a switch, you have interrupted the permanent live somewhere, if the trip on the consumer unit is identified , drop it completely to off the reset back to on, some have a duel setting and if you touched the Earth wire it drops out but doesnt always look like it has, if none of that works show a pic of how the nest is wired at the boiler end

I've just changed the fuse in the spur (checked the fuse from the spur in another appliance which worked fine) and reconnected the old thermostat and still no power. I switched the CU off and on before reconnecting everything. Thinking about it, I should have probably done this after so I'll go and do it again now.

I've also taken photos of how the wiring is inside the boiler for reference.

** Edit **
Turns out I was taking the spur to be the one outside of the boiler. I've just found the one inside the boiler and changed that which has worked with the old thermostat. I'll rewire for the nest and check again (and also buy a shed load more of these fuses!)

** Update **
Nest now working fine and so is the boiler. Thanks for the help Ian, very much appreciate it! Would have been without heating and hot water this week if you hadn't have helped! Thanks again.

 

[Deleted member 267285]

I suppose it depends if the boiler supply was wired through the thermostat? You have a brown in common at the Nest e, but on the old was black? Also get some sleeving or change the wire for the cpc/Earth being used as a live/line conductor. Check for additional fused connection unit switches, seen that before now as well.