Nest and Opentherm
Discussion
Hi,
I have posted this on a couple of forums... wondered if anyone on here might have an idea as I know a few of you understand smart heating controls.
So the issue is with my newly installed heating system and it is this:
[*]The system is a Intergas Eco RF 24 running as a heat only system boiler with a 3rd generation nest and a Joule unvented cylinder
[*]It is an S-Plan set up with two Honeywell zone valves, one for hot water one for heating
[*]Nest is connected to the boiler by the two OpenTherm wires and is mounted on the wall, powered by some other wires the installer re-used - so it is not on the USB plug adapter that comes with it
[*]The heating functions perfectly - when called the boiler fires up, the zone valves open and the radiators warm up. The flow temp can be adjusted by the nest, everything works as it should. Boiler modulates nicely and the nest holds the house and a steady temp really well
[*]The nest is set to OpenTherm for heating and "on/off" for hot water, and is set as a system boiler
[*]If hot water heating is called for the zone valve opens and the water tank is heated ONLY if the radiator heating is going.
[*]If there is no heating called for , and you just ask for water on its own, the zone valve opens but the boiler does not fire. My understanding is the boiler should fire at it's max flow temp when hot water is demanded until the target temp is reached.
[*]My Nest shows software version 5.6 1-4
Nest have made two visits (well not nest it is Help Link, and they are just not that well versed in Openther, connections). Installer has been back numerous times and we did add a switched live from the hot water zone valve to the boiler. This did make the boiler fire for hot water demand, but it sent it a bit crazy, cycling on and off every 90seconds or so. This has been removed.
I have three options now the way I see it....
Find some sort of fault with the set up and magically it all starts working
Send it back and go for something different. Debating Tado.
Abandon the whole OpenTherm thing and set it all up as just on/off
Any help anyone can provide would be massively appreciated. I'm at an absolute loss! Nest and intergas have been pretty useless.
I have posted this on a couple of forums... wondered if anyone on here might have an idea as I know a few of you understand smart heating controls.
So the issue is with my newly installed heating system and it is this:
[*]The system is a Intergas Eco RF 24 running as a heat only system boiler with a 3rd generation nest and a Joule unvented cylinder
[*]It is an S-Plan set up with two Honeywell zone valves, one for hot water one for heating
[*]Nest is connected to the boiler by the two OpenTherm wires and is mounted on the wall, powered by some other wires the installer re-used - so it is not on the USB plug adapter that comes with it
[*]The heating functions perfectly - when called the boiler fires up, the zone valves open and the radiators warm up. The flow temp can be adjusted by the nest, everything works as it should. Boiler modulates nicely and the nest holds the house and a steady temp really well
[*]The nest is set to OpenTherm for heating and "on/off" for hot water, and is set as a system boiler
[*]If hot water heating is called for the zone valve opens and the water tank is heated ONLY if the radiator heating is going.
[*]If there is no heating called for , and you just ask for water on its own, the zone valve opens but the boiler does not fire. My understanding is the boiler should fire at it's max flow temp when hot water is demanded until the target temp is reached.
[*]My Nest shows software version 5.6 1-4
Nest have made two visits (well not nest it is Help Link, and they are just not that well versed in Openther, connections). Installer has been back numerous times and we did add a switched live from the hot water zone valve to the boiler. This did make the boiler fire for hot water demand, but it sent it a bit crazy, cycling on and off every 90seconds or so. This has been removed.
I have three options now the way I see it....
Find some sort of fault with the set up and magically it all starts working
Send it back and go for something different. Debating Tado.
Abandon the whole OpenTherm thing and set it all up as just on/off
Any help anyone can provide would be massively appreciated. I'm at an absolute loss! Nest and intergas have been pretty useless.
I had a very similar problem,
Our boiler wouldn't fire when using the opentherm connections, rewired into the Heat Call and Hot Water call and its working OK. Effectively is just on/off now.
The boiler is set to max for both hot water and heating, when the thermostat notices its cold it then fires the heating for a set time until is reach almost the temperature then shuts down allowing for the residual heat in the rads to heat the last few degrees.
Re NestPro Installers, I was made a NestPro Installer before I had even seen one. I have fitted one at home and wanted more to be able to supply them as part of packages in Home Automation. A lot of NestPro installers like me have little or no idea about boilers.
Our boiler wouldn't fire when using the opentherm connections, rewired into the Heat Call and Hot Water call and its working OK. Effectively is just on/off now.
The boiler is set to max for both hot water and heating, when the thermostat notices its cold it then fires the heating for a set time until is reach almost the temperature then shuts down allowing for the residual heat in the rads to heat the last few degrees.
Re NestPro Installers, I was made a NestPro Installer before I had even seen one. I have fitted one at home and wanted more to be able to supply them as part of packages in Home Automation. A lot of NestPro installers like me have little or no idea about boilers.
Thanks for the reply.
This is what I feared - it just doesn't seem to work. I am wondering if I scrap it and go for tado - but again unsure if I will run into the same problems.
An installer over on another forum says he has got the exact same configuration as mine to work fine, just seems off the opentherm controls heating fine, but won't do hot water.
This is what I feared - it just doesn't seem to work. I am wondering if I scrap it and go for tado - but again unsure if I will run into the same problems.
An installer over on another forum says he has got the exact same configuration as mine to work fine, just seems off the opentherm controls heating fine, but won't do hot water.
panholio said:
Thanks for the reply.
This is what I feared - it just doesn't seem to work. I am wondering if I scrap it and go for tado - but again unsure if I will run into the same problems.
An installer over on another forum says he has got the exact same configuration as mine to work fine, just seems off the opentherm controls heating fine, but won't do hot water.
OK mine on Opentherm wouldn't fire the boiler for either hot water so went to on/off. To be fair it works!This is what I feared - it just doesn't seem to work. I am wondering if I scrap it and go for tado - but again unsure if I will run into the same problems.
An installer over on another forum says he has got the exact same configuration as mine to work fine, just seems off the opentherm controls heating fine, but won't do hot water.
Not sure if its a Nest thing or not. Try a plumber as Nest is technically just a thermostat. Give a few local guys a ring around and see if any of them are able to help.
chasingracecars said:
OK mine on Opentherm wouldn't fire the boiler for either hot water so went to on/off. To be fair it works!
Not sure if its a Nest thing or not. Try a plumber as Nest is technically just a thermostat. Give a few local guys a ring around and see if any of them are able to help.
Just to clarify, are the Honeywell zone valves connected to the Nest Heat Link?Not sure if its a Nest thing or not. Try a plumber as Nest is technically just a thermostat. Give a few local guys a ring around and see if any of them are able to help.
Any update on this?
I'm just having an Ideal Vogue system boiler put in, and a Nest V3. The boiler is Opentherm compatible in theory, I have mentioned this is what I would like to the plumber but he doesn't seem to have heard of Opentherm. What he's planning on doing sounds like there is a heating/wiring box that the boiler and S-plan valves and Nest (presumably the Heat Link) wire in to. From what I've seen the Heat Link should connect directly to the boiler with Opentherm? Does the boiler then control the S-Plan valves?
I'm just having an Ideal Vogue system boiler put in, and a Nest V3. The boiler is Opentherm compatible in theory, I have mentioned this is what I would like to the plumber but he doesn't seem to have heard of Opentherm. What he's planning on doing sounds like there is a heating/wiring box that the boiler and S-plan valves and Nest (presumably the Heat Link) wire in to. From what I've seen the Heat Link should connect directly to the boiler with Opentherm? Does the boiler then control the S-Plan valves?
Just trying to get up to speed on this and it seems like what he is thinking of is what is standard on a V2, described here:
https://nest.com/uk/support/article/Which-cables-c...
V2:
V3:
https://nest.com/uk/support/article/Which-cables-c...
V2:
V3:
For reference, here's the V3 wiring diagrams:
https://nest.com/support/images/misc-nest-thermost...
On page 26 the Opentherm wiring seems to show that you only need OT1 and OT2. Is that literally it?
Also on page 24 the 'S-plan' wiring shows all sorts of connections. If you have an Opentherm boiler do you not need the S-plan valves, or are they just not talked to by the Nest (i.e. Nest tells boiler what to do, boiler in turn tells the valves to open)?
https://nest.com/support/images/misc-nest-thermost...
On page 26 the Opentherm wiring seems to show that you only need OT1 and OT2. Is that literally it?
Also on page 24 the 'S-plan' wiring shows all sorts of connections. If you have an Opentherm boiler do you not need the S-plan valves, or are they just not talked to by the Nest (i.e. Nest tells boiler what to do, boiler in turn tells the valves to open)?
panholio said:
Hi,
I have posted this on a couple of forums... wondered if anyone on here might have an idea as I know a few of you understand smart heating controls.
So the issue is with my newly installed heating system and it is this:
[*]The system is a Intergas Eco RF 24 running as a heat only system boiler with a 3rd generation nest and a Joule unvented cylinder
[*]It is an S-Plan set up with two Honeywell zone valves, one for hot water one for heating
[*]Nest is connected to the boiler by the two OpenTherm wires and is mounted on the wall, powered by some other wires the installer re-used - so it is not on the USB plug adapter that comes with it
[*]The heating functions perfectly - when called the boiler fires up, the zone valves open and the radiators warm up. The flow temp can be adjusted by the nest, everything works as it should. Boiler modulates nicely and the nest holds the house and a steady temp really well
[*]The nest is set to OpenTherm for heating and "on/off" for hot water, and is set as a system boiler
[*]If hot water heating is called for the zone valve opens and the water tank is heated ONLY if the radiator heating is going.
[*]If there is no heating called for , and you just ask for water on its own, the zone valve opens but the boiler does not fire. My understanding is the boiler should fire at it's max flow temp when hot water is demanded until the target temp is reached.
[*]My Nest shows software version 5.6 1-4
Nest have made two visits (well not nest it is Help Link, and they are just not that well versed in Openther, connections). Installer has been back numerous times and we did add a switched live from the hot water zone valve to the boiler. This did make the boiler fire for hot water demand, but it sent it a bit crazy, cycling on and off every 90seconds or so. This has been removed.
I have three options now the way I see it....
Find some sort of fault with the set up and magically it all starts working
Send it back and go for something different. Debating Tado.
Abandon the whole OpenTherm thing and set it all up as just on/off
Any help anyone can provide would be massively appreciated. I'm at an absolute loss! Nest and intergas have been pretty useless.
Hi, I'm having the exact same problem, I'd never installed a boiler using opentherm before so thought I'd try it at home to see what it was like. As you say, all connections to the valves are made in addition to the two extra cores for the opentherm, from heat link to boiler and like you, the heating part works fine. However when heating is not calling, but hot water is, the motorised valve opens as it should and supplies the normal switched live to the boiler, but it doesn't fire. Almost as if it requires some sort of opentherm enabled cylinder thermostat or something? I have posted this on a couple of forums... wondered if anyone on here might have an idea as I know a few of you understand smart heating controls.
So the issue is with my newly installed heating system and it is this:
[*]The system is a Intergas Eco RF 24 running as a heat only system boiler with a 3rd generation nest and a Joule unvented cylinder
[*]It is an S-Plan set up with two Honeywell zone valves, one for hot water one for heating
[*]Nest is connected to the boiler by the two OpenTherm wires and is mounted on the wall, powered by some other wires the installer re-used - so it is not on the USB plug adapter that comes with it
[*]The heating functions perfectly - when called the boiler fires up, the zone valves open and the radiators warm up. The flow temp can be adjusted by the nest, everything works as it should. Boiler modulates nicely and the nest holds the house and a steady temp really well
[*]The nest is set to OpenTherm for heating and "on/off" for hot water, and is set as a system boiler
[*]If hot water heating is called for the zone valve opens and the water tank is heated ONLY if the radiator heating is going.
[*]If there is no heating called for , and you just ask for water on its own, the zone valve opens but the boiler does not fire. My understanding is the boiler should fire at it's max flow temp when hot water is demanded until the target temp is reached.
[*]My Nest shows software version 5.6 1-4
Nest have made two visits (well not nest it is Help Link, and they are just not that well versed in Openther, connections). Installer has been back numerous times and we did add a switched live from the hot water zone valve to the boiler. This did make the boiler fire for hot water demand, but it sent it a bit crazy, cycling on and off every 90seconds or so. This has been removed.
I have three options now the way I see it....
Find some sort of fault with the set up and magically it all starts working
Send it back and go for something different. Debating Tado.
Abandon the whole OpenTherm thing and set it all up as just on/off
Any help anyone can provide would be massively appreciated. I'm at an absolute loss! Nest and intergas have been pretty useless.
I would normally consider myself quite well versed when it comes to heating systems but this has me stumped and no body I've spoken to has any idea either.
So wondering if you had any luck or did you, like me, have to revert back to on/off controls and abandon the opentherm altogether?
Cheers
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