Opentherm Capabilities connected to Navien LCB700 boiler

[RoyCruse]

Hi,

I have just had fitted a Navien LCB700 Modulating Oil Combi Boiler, Ive connected up my 3rd gen nest thermostat and ive got basic control but some of it is not working as id expect...   How can i find out what parts of the opentherm protocol are supported between these two units so that i can adjust my expectations and test accordingly.

[TudorL]

Hi there and thanks for reaching our Community. I'm sorry about the issue you're facing, but I'll do my best to help you out. Could you please tell me if there are any error codes on the thermostat display at this moment? 

Additionally, please check if you set up the controls properly in Pro Setup. You can check this by going to the thermostat display, access Settings -> Equipment -> Pro Setup, and changing the controls according to the characteristics of your own heating system. 

[AlexD]

Hi, I wanted to check in. Did you see the message from my colleague? If you need further assistance, make sure to let me know. 

[RoyCruse]

Yes i saw the reply from TudorL but unfortunatyely he didnt answer my question and just asked a different question.
No, there are no error codes and yes its setup for an oil boiler - i used custom settings so I could set both CH and DHW to opentherm.

My question is how can i tell what parts of the opentherm protocol are supported with this controller / boiler combo.   there is no log files or advanced screens where i can see the opentherm communication log - its such a shame as this stuff is really usefull for understanding and debugging whats going on with the heating system.   In fact its almost essential as theres no longer simple on off commands between controller and boiler i need to know whats being asked of the boiler to even have a chance of knowing its working correctly

[AlexD]

Thank you for all the information. When it comes to the OpenTherm protocol there are different variants.

You can check out this link here for more information on compatibility. In short, if your boiler has that sign mentioned there, it should be compatible. If it does not, it does not mean it can't work, but it needs to be looked at by a boiler specialist to see if it is possible to make it work. That page also contains some other information on the functionality with OpenTherm. 

You mentioned it seems to be working but not as you'd expect. Could you expand on that? 

[RoyCruse]

so "in short" no one knows - and theres no way to find out.

the opentherm protocol involves a handshake where the supported features arte exchanged - Nest doesnt give you any feedback as to what the result of this is.   as an example i change my DHW temp and nothing happens at the boiler end - is this becuase the boiler is ignoring my changes or becuase the temp is not supported or becuase nest isnt sending them, etc etc   i have no way of knowing

I think im selling my nest and moving to Tado   

I feel like the nest product hasnt changed in 5 years - theres no TRVs that can demand heat - in fact theres no way to warm up your bedroom without the stat in the lounge calling for heat.   such an antiquated system when you compare to the competition.

you cant even get graphs of temperature vs demand etc.

basically theres no way to know whats going on other than what the room feels like.

[AlexD]

Thank you for all the feedback. Our engineers are always looking for ways to improve both our products and services. 

There are no graphs or information on how the OpenTherm protocol communicates and what information is exchanged. Generally these systems will run constantly and depending on the request, for example requesting heat, and vary the temperature of the water in the system, of the flame, to the maximum set in the thermostat settings, to achieve that requested temperature. 

There is some information on the heating that you can see in the Home report, you can read more about it here. 

Again, thank you for all the feedback shared. 

[LarisaL]

Hi there, just checking in! Did you see the message from my colleague?

[RoyCruse]

yes i saw the response but im looking for a way to debug and analyse whats working and not working and why.

Im not sure nest or my boiler is going to give me that info. such a shame - any interface needs a method to see if its working or not.

[AlexD]

You can check if the boiler has any additional information however the thermostat only has the Home Report.

We can do a few tests to make sure the thermostat is sending the commands to the boiler and that it reacts accordingly. To turn the heating on and off, and to perhaps change the temperature of the hot water in the settings and if the boiler has a display, see if it reflects this changes. Is that something you would wish to try? 

[UanaC]

Hi! Just checking in with you, did you see my colleagues previous message?

[AlexD]

Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks, AlexD.