Atag One replacement

[brewmook]

The Nest E is working, but I'd agree the modulation is quite "different". I've not had it in long enough to really get a good impression yet.

I really miss being able to see the set point and flow/return temp from the app. I'd like to explore the API some day, though probably I'll never have time.

 

[king of pipes]

Hi everyone,

I have purchased a Nest 3rd Learning for my ATAG I28C (I-Serie 2016 year) and it works pretty well.
Unfortunally modulation is not perfect like weather compensation mode (without ambient controller, only external temperature probe connected to the boiler).
I bought the Nest for a smarter and tighter heating managment but when ambient temperature reach the set-point, Nest turns off the boiler.
Furthermore I must strictly set the maximium heating water temperature , because it seems that sometimes Nest raise up the water temperature to the maximum value.
At this point I would ask to King of Pipes, if he has the ATAG BCU (of One kit) between ATAG boiler and Nest Heat Link (I suppose that you have the same model of me - 3rd Learning).
TY
Paolo

No I don't have the module fitted just 3rd generation Nest and heatlink wired to opentherm connections in the boiler Atag ic27 economiser . Kop

 

[PaoloTherm]

No I don't have the module fitted just 3rd generation Nest and heatlink wired to opentherm connections in the boiler Atag ic27 economiser . Kop

Ok, and do you observe the effect of modulation? In my case, the boiler works at the maximum temperature value that I have set on the thermostat and on the boiler panel. Obviously i've also setted Opentherm mode into the settings menù of the Nest, but it doesn't matter: when set point ambient temperature is reached, the boiler turns off (for the joy of the reporting section! -_-"").

 

[PaoloTherm]

and then... and then in a GERMAN boiler manual you find that "The following (clock) thermostats can be connected to the ATAG i-Series:

• Bus: connect the ATAG One directly to the BUS position.
• Bus+OT-LPA1): connect a Round Modulation, WiZe or OpenTherm thermostat/controller on OT-LPA (1) and then on OT-LPA in position

BUS (2). See figure 9.1.a.

1) OT-LPA stands for OpenTherm Low Power Adapter.
This adapter must be between the autopilot and
thermostat/regulator be connected, if
there is an ATAG WiZe, Round Modulation or other OpenTherm controller is used".

OT-Adapter is a ridiculous little circuit to be applied in series between the cable coming from Opentherm interface (Nest Heatlink in this case) and the boiler control board. Maybe I'll try it, but I have to find it before.
Meanwhile, I'm speechless, I just say DAMN!

Why informations are soooo fragmented?! --..--