Home Automation Domotica Forum Europe, Bwired Forum

Hi all,

I already saw some topics here about this but I’m still in the dark a little bit.

I was looking into advice for ordering my new gas boiler heating system and the most convenient way to set it up.
At this moment we have no heating so everything is free of choice as we speak, except is should be gas heating. (Old house)

The heating elements are already setup:
One circuit is floor heating
Al the other rooms are standard heating radiators. Comes down to 7 separate zones.
And hot water circuit for bathroom and kitchen. (that's probably managed by the boiler itself.)

If possible, I would like to manage all rooms separately. Every room has now a Xiaomi Mijia temperature sensor connected to home assistant. The idea would be to put electric thermal actuators on the collector for each circuit and control those via home assistant and control the CV with home assistant over the opentherm gateway.

Is it overall a good idea to use home assistant for all heating? Are manufacturers thermostats combinable with the use of OTGW plus HA? Eg eBus and OTGW together? Or even add an Nest thermostat into the setup?

And if it’s a good idea, what boiler manufacturer would be the most convenient to choose for use of the opentherm gateway? I’ve been reading that Vaillant BE (I’m located in Belgium) not support OTGW but the VR33 card can be orderd in the Netherlands. And is mostly usable.

Sorry, I know it’s a lot and also my first post.

Greetz,
Ward

It's up to the thermostat to handle things like multiple zones and floor heating. I would definitely suggest to get a boiler that supports Opentherm to avoid vendor lock in, which may severely limit your choice of thermostats and the ability to control your system via home automation. The only other consideration on the boiler side might be if you want to splash out for a unit that has two separate heating circuits: One for the floor heating and one for the radiators. But as far as I know, this can also be managed externally with a boiler with only one heating circuit.

One thing I would want in my next boiler is a DC pump. They consume much less electricity than an AC pump. This may actually already be the standard by now, or even a requirement from the EU as part of the effort to reduce carbon dioxide emissions. You may also want the boiler to support certain nice to have messages, such as CH water pressure (message ID 18). The equipment matrix may be of some assistance in making this selection. I would definitely avoid boilers that do not support the maximum relative modulation level setting (message ID 14). Finally, it is my impression that boilers that insist on doing their own low-load control (ID3:HB4) produce a less comfortable experience than when low-load control is done by the thermostat.

Disclaimer: I still use a simple traditional setup myself: A single-circuit boiler with only radiators, controlled by a thermostat in the living room. So the information I provided above is in large part based on theory rather than experience. Hopefully it is of some help anyway.