I use a heating boiler, namely the Atag TY36E20H I36ECZ.
This boiler was installed about two years ago to replace the old (probably
non-modulating) Nefit combi-boiler.
I use a 3rd generation nest learning thermostat. I also used this thermostat
with the Nefit.
Since the installation of the new boiler I have had a problem: I have set a
fixed schedule in my 3rd generation nest learning thermostat. So I have
turned off autolearning. This means that according to this schedule the
temperature should be at 19 degrees every morning at 7 o'clock. However, it
takes (depending on the outside temperature) until 7.45 or 8 o'clock before
the set temperature is reached. So almost an hour too late. The settings of
the thermostat, especially true radiant are good. True radiant is turned on.
I did not have this problem with the Nefit boiler.
In the meantime, one of the heating boiler technicians has looked at the
problem three times. According to the CV fitter, the Combi boiler has no
problems. The capacity would also be more than sufficient. The fitter could
not give me a solution.
However, the last fitter indicated that a Nest thermostat works with a
different protocol than a modulating Atag boiler.
According to the internet, this problem could be solved by installing a BCU
module.
I have contacted the Google Nest customer service. They refer me to a
certified installer. Atag refers me to the installer of the boiler.
My question is:
- could the problem be caused by the fact that the Atag boiler may not
communicate properly with the Nest thermostat?
- could it mean that the Nest thermostat is defective?
- what other cause could it have?
