Nest, OpenTherm and the Remeha Avanta Plus

[madgeni]

Hi all

I've just bought a NEST 3rd gen, and would like to use OpenTherm. The Nest 'doc' has me just using the OT terminals to control the boiler, but i've also read that it's a standard wiring (i'll replace the programmer) PLUS the OT.

Does anyone have any experience with this? I've scanned the various topics, but none seem to cover OT (i know it's only been available via a firmware release for a short(ish) time).

Cheers, and appreciate any advice

 

[hertsboilers]

According both of the manuals, remove the link between 7 and 8 on terminal block X9, link them to OT1 and OT2 of the Nest Heatlink.

 

[muggles]

As above - connect Live, Neutral, OT1 and OT2 only.

 

[madgeni]

Thanks hertsboilers - appreciate the response. That's how i read it, however according to a.n.other site:
"This is Fergus from the Nest VIP Support team. I hope you are well.
..For system boilers you would still wire the terminals accordingly to the normal wiring diagrams, then connect the OpenTherm wiress (OT1 and OT2) in addition"

I'm assuming that's what I need to do? It just runs contrary to the instructions

Thanks Muggles - am i overcomplicating it?

 

[iMarkG84]

I have recently installed the Nest v3 on a new set up. Ideal System 24 (with OT) and a Tribune XE water tank. Central heating is working, but we can't get the call for Hot Water to turn on the boiler - only flick the valve to allow water flow through the Tank - HELP!

 

[hertsboilers]

I have recently installed the Nest v3 on a new set up. Ideal System 24 (with OT) and a Tribune XE water tank. Central heating is working, but we can't get the call for Hot Water to turn on the boiler - only flick the valve to allow water flow through the Tank - HELP!

Two of two port valves for S plan? Might be a faulty valve for hot water.

 

[iMarkG84]

Yeah it's a two of two port s plan. The valve works. It's something between the heatlink and boiler. It's not switching the boiler on, only swithcing the valve. CH works fine.

 

[Agile]

Are you sure that you don't need to change boiler setup parameters?

Some of these Nest installs are not quite as DIY as many people think they are!

Tony

 

[snb]

With a remeha you cannot have OT controls with 2 x 2 ports. You will have to re pipe using a divertor valve and make it hot water priority. You will then need to change a few parameters. This info is in the manual. There is a separate manual called wiring schematics which has the wiring and pipework setup to enable what you are after.