Nest Thermostat can't detect OpenTherm connection on a Baxi boiler

[PedroM]

Hi,

I live in Lisbon and I've just installed a Baxi combi boiler and connected it with a Google nest 3rd generation thermostat as the picture below depicts.

The issue is that the nest thermostat can't detect the Boiler's OpenTherm connection and displays the following error:

Does anyone has any clue on this issue?

Any help is much appreciated.
Thank you,
Pedro.

 

[ShaunCorbs]

Need to leave the link in

 

[PedroM]

Need to leave the link in

Hi Shaun,

Thank you so much for your prompt reply. I had tried before but I've tried once again with the link on (see picture) but I get the the exact same error. I've cut the power to the boiler and heat link and I've restarted the Thermostat but nothing changed.

Do you have any other suggestions?

Thanks in advance. Regards,
Pedro.

 

[ShaunCorbs]

Would say you have a bad nest then

 

[Ziggie13]

Did you have a “Main” controller managing the system before putting in the Nest?

The system in a relatives house simply works by supplying an off on switch to the boiler.

I don’t have the system manuals handy so I don’t know if the boiler supports opentherm - but I presume you know.The boiler may be an earlier model.

 

[PedroM]

Did you have a “Main” controller managing the system before putting in the Nest?

The system in a relatives house simply works by supplying an off on switch to the boiler.

I don’t have the system manuals handy so I don’t know if the boiler supports opentherm - but I presume you know.The boiler may be an earlier model.

Hi Ziggie,

Thanks for your reply.
I've replaced the old boiler and thermostat at once.
I'm 100% sure that the new boiler support opentherm.

Now I just don't know how to troubleshoot this issue, at least to determine in which side the problem lies, i.e., if it's a nest heatlink issue or a boiler issue. I guess I would have to try with another thermostat...

Best regards,
Pedro.

 

[Stormtrooper56]

Hi I have the same issue, did you ever get this resolved?

 

[king of pipes]

I had a similar issue on my own system my nest heat link was originally hard wired , to get a open therm setting on the thermostat I had to do a factory default reset on the heat link , then go through the settings connecting the thermostat to a wired and wireless connection , I could connect the thermostat via opentherm in the Nest pro settings to the boiler worth a try ? . Nest customer service are good they can talk you through the setting the stat over the phone if it turns out to be faulty they will replace it but will want the faulty one sent back to them, I had one replaced with a software issue they sent me the packaging to return the Thermostat then sent out a replacement. Regards Kop

 

[Frodo34]

@PedroM @Stormtrooper56 did you ever get this resolved? I have a similar issue with a Baxi 800 boiler, pretty much same connections and setup, except I have the thermostat on a stand. H73 error showing on thermostat - wonder if this is a common problem with this boiler? The "On/Off" works absolutely fine no issue, its just the OpenTherm it cannot detect.

 

[Lou]

(Just bumping a few older threads, they will drop off what is new soon)

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