Nest 3rd Gen | Heat Link | OpenTherm | Clicking but no heating

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Hi all, I'm looking for some advice on my self-installation of my NEST 3rd generation thermostat. I previously installed this set-up in my old property which had the same boiler and everything worked. Recently moved properties and set-up the nest again and my issues have begun...

Just looking for some advice, before getting an engineer out as this set-up worked previously so not sure if ive missed something.

Boiler: IDEAL Logic ESP 35

Heat link L+N to Boiler L+N
OpenTherm connection in the boiler connected
2 cables from OT1 + OT2 in Heat Link to OT points in boiler.
Utilized existing thermostat cables to power the nest itself.

The heatlink has a green static LED and the NEST powers on and connects fine, however when changing the temp on the NEST, i hear the Heat Link click acknowledging the nest change of temp, however, the boiler remains in standby "00" waiting for a call for heat I believe.

I should add, when pressing the Heat Link button, all heating and water lights turn green however the heating still does not turn on.

Cant any body shed some light?

Photos attached, thanks.

Thanks,
Callum
 
Last edited:
You shouldn't be removing the casing of that boiler unless you're Gas Safe Registered. It forms the safety room seal and the boiler should not be operated again until a competent person has carried out the regulation 26.9 checks. They can probably troubleshoot your Nest installation issues too...

Sorry, probably not the answer you're looking for but forum rules dictate that we can't give advice which might impinge on appliance (and therefore your) safety - in your case, that means anything which involves removing the cover
 
How stupid is this?

upload_2019-6-4_14-14-49.png
 
Thanks for the response and advice.
Looks like I'll have to get the engineer out!

@ EFLImpudence thanks for the input :- I was briefly connecting this to check it was all working before cabling/connecting and terminating correctly. Thanks anyways.
 
You shouldn't be removing the casing of that boiler unless you're Gas Safe Registered. It forms the safety room seal and the boiler should not be operated again until a competent person has carried out the regulation 26.9 checks. They can probably troubleshoot your Nest installation issues too...

Sorry, probably not the answer you're looking for but forum rules dictate that we can't give advice which might impinge on appliance (and therefore your) safety - in your case, that means anything which involves removing the cover

Thanks Muggles, might not have been the advice but if those are the rules then so be it.
I actually went home and re-wired the NEST using the call for heat and managed to get everything working. Also called on a GAS Safe mate to pop round to check everything and other than the colour choice of a blue wire, is good. He also carried out the all the checks and serviced the boiler for me whilst he was there.

All in all, i have a serviced boiler with a fully working NEST, thanks for the help
 
It's a shame that you didn't get your Gas Safe mate to set up the OpenTherm properly whilst he was there. OT provides enhanced control compared to the basic 'call for heat' on/off switch. Ive found that when OpenTherm doesn't work it's down to the Nest settings not being configured properly, or the link wire in the boilers thermostat terminals being removed when some boilers require it to stay in place when running on OT.
 
He did actually do that for me, but it looked like a faulty OT harness on my boiler, rather than messing about ordering a new one to try i just said to leave as is.
We both checked the settings on the NEST and changed the settings in PRO mode to OT etc but still nothing.
OpenTherm is definitely the better option to wire up though.
 
Did you note the extra part when wiring in the OT ? cant remember exactly but you have to remove the timer link and join it to some other plug and put a rubber bung where the timer link was , it will be in the boilers MIs @shambolic will know
 
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