Evohome + Opentherm + Viessmann Vitodens 100
Re: Evohome + Opentherm + Viessmann Vitodens 100
I'm looking at introducing a Opentherm gateway between the evohome and my Vitodens 100 to allow me to control the flow temperature manually or even possibly automatically from climate/ seasonal data.
Has anyone had experience with this DIY gateway project? http://otgw.tclcode.com
Having done a small amount of research it would seem possible to relay the R8810A & boiler opentherm commands through the gateway but crucially also allowing the addition of the temp flow ID data set on the gateway to be passed to the boiler.
Even though the project is somewhat DIY you can purchase pre-assembled boards for those less handy with a soldering iron (like me!) https://www.nodo-shop.nl/en/48-opentherm-gateway
Thoughts on the above would be welcomed.
Stu
Has anyone had experience with this DIY gateway project? http://otgw.tclcode.com
Having done a small amount of research it would seem possible to relay the R8810A & boiler opentherm commands through the gateway but crucially also allowing the addition of the temp flow ID data set on the gateway to be passed to the boiler.
Even though the project is somewhat DIY you can purchase pre-assembled boards for those less handy with a soldering iron (like me!) https://www.nodo-shop.nl/en/48-opentherm-gateway
Thoughts on the above would be welcomed.
Stu
Re: Evohome + Opentherm + Viessmann Vitodens 100
I have lyrics t6R, with the same problem with opentherm. Viessmann does not help, says this is honeywell's fault. But I can set parameters in the thermostat. Software update resolves the problem so that I can set maximum heating water. Now I can set hot water temp. Why does not honeywell do it?
Re: Evohome + Opentherm + Viessmann Vitodens 100
The problem doesn't reside with Honeywell, the problem is with Viessmann for not allowing a maximum central heating temperature setpoint at the boiler.baloghta wrote:I have lyrics t6R, with the same problem with opentherm. Viessmann does not help, says this is honeywell's fault. But I can set parameters in the thermostat. Software update resolves the problem so that I can set maximum heating water. Now I can set hot water temp. Why does not honeywell do it?
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
Honeywell fully complies with the requirements of the OpenTherm spec and this does not state that OpenTherm controls MUST control the maximum central heating temperature setpoint. A decent OpenTherm boiler following the OpenTherm specification, will allow this to be set manually at the boiler (as Intergas boilers do).
This is very much a Viessmann problem and if Honeywell choose to control DHW temp setpoint and CH temp max then this is in addition to what is 'REQUIRED'...
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Re: Evohome + Opentherm + Viessmann Vitodens 100
Thanks for the answer. What do you recommend? Do I use with opentherm or on / off relay?The EVOHOME Shop wrote:The problem doesn't reside with Honeywell, the problem is with Viessmann for not allowing a maximum central heating temperature setpoint at the boiler.baloghta wrote:I have lyrics t6R, with the same problem with opentherm. Viessmann does not help, says this is honeywell's fault. But I can set parameters in the thermostat. Software update resolves the problem so that I can set maximum heating water. Now I can set hot water temp. Why does not honeywell do it?![]()
Honeywell fully complies with the requirements of the OpenTherm spec and this does not state that OpenTherm controls MUST control the maximum central heating temperature setpoint. A decent OpenTherm boiler following the OpenTherm specification, will allow this to be set manually at the boiler (as Intergas boilers do).
This is very much a Viessmann problem and if Honeywell choose to control DHW temp setpoint and CH temp max then this is in addition to what is 'REQUIRED'...
Re: Evohome + Opentherm + Viessmann Vitodens 100
The documentation said:
https://www.honeywelluk.com/Documents/F ... 0sheet.pdf
Max Supply Water Setpoint 90 30 tot 90 °C (appliance depending) - future
"future"?![Smile :)](./images/smilies/icon_e_smile.gif)
https://www.honeywelluk.com/Documents/F ... 0sheet.pdf
Max Supply Water Setpoint 90 30 tot 90 °C (appliance depending) - future
"future"?
![Smile :)](./images/smilies/icon_e_smile.gif)
Re: Evohome + Opentherm + Viessmann Vitodens 100
I would recommend you get a decent OpenTherm boiler...baloghta wrote:Thanks for the answer. What do you recommend? Do I use with opentherm or on / off relay?
![Wink ;)](./images/smilies/icon_e_wink.gif)
If you read the section its says 'read only' as in this is data you can obtain from the boiler over OpenTherm in a 'read only' format. AFAIK, there are no plans currently by Honeywell to have the thermostat set max flow temp.baloghta wrote:The documentation said:
https://www.honeywelluk.com/Documents/F ... 0sheet.pdf
Max Supply Water Setpoint 90 30 tot 90 °C (appliance depending) - future
"future"?
Home: 2012 Built Oak & Timber Frame Home (EPC Score 95 - A Rated)
Renewable Tech: GSHP, Solar Thermal, Solar PV & 20kWh Battery Storage
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Re: Evohome + Opentherm + Viessmann Vitodens 100
I have a viessmann boiler, I can not change it, I do not want it.The EVOHOME Shop wrote:I would recommend you get a decent OpenTherm boiler...baloghta wrote:Thanks for the answer. What do you recommend? Do I use with opentherm or on / off relay?![]()
If you read the section its says 'read only' as in this is data you can obtain from the boiler over OpenTherm in a 'read only' format. AFAIK, there are no plans currently by Honeywell to have the thermostat set max flow temp.baloghta wrote:The documentation said:
https://www.honeywelluk.com/Documents/F ... 0sheet.pdf
Max Supply Water Setpoint 90 30 tot 90 °C (appliance depending) - future
"future"?
![Smile :)](./images/smilies/icon_e_smile.gif)
Opentherm or not?
Re: Evohome + Opentherm + Viessmann Vitodens 100
OpenTherm is great, but maybe W/C hybrid if max flow temp can't be adjusted?
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Re: Evohome + Opentherm + Viessmann Vitodens 100
What is W/C hybrid?The EVOHOME Shop wrote:OpenTherm is great, but maybe W/C hybrid if max flow temp can't be adjusted?
![Shocked :shock:](./images/smilies/icon_eek.gif)
Re: Evohome + Opentherm + Viessmann Vitodens 100
Exactly...baloghta wrote:What is W/C hybrid?The EVOHOME Shop wrote:OpenTherm is great, but maybe W/C hybrid if max flow temp can't be adjusted?
![Wink ;)](./images/smilies/icon_e_wink.gif)
![Laughing :lol:](./images/smilies/icon_lol.gif)
Home: 2012 Built Oak & Timber Frame Home (EPC Score 95 - A Rated)
Renewable Tech: GSHP, Solar Thermal, Solar PV & 20kWh Battery Storage
Smart Home Platform: Home Assistant, Shelly & Salus Smart Home
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