Viessmann Vitodens 111

[cagnulein]

Hi everybody, i've discovered this great project just few days ago and i would like to set up immediately!
I would like just to be sure if OTGW fits my needs.
I have a Vitodens 111. First question here: is it compatible? I saw that the little sister Vitodens 100 is compatible, so i guess (maybe wrong) that it could be too.

I would like to use OTGW without a thermostat: i have already the thermostats in each room but they simply turn on/off valves in order to enable the flow of the hot water inside my floor. So i would like only to be able to setup the setpoint of the Vitodens and read some parameters. Of course i would like to do these operations from internet.

I think OTGW should be perfect for my needs. What do you think?
Thanks
Roberto

[marcelr]

According to the installation manual, the Vitodens 111 has an OT interface. Therefore I think it should be compatible.
Possibly superfluous, but just so you know: Setting the room temperature for a modulating boiler requires a controller. The setpoint for the boiler, as generated by an OT thermostat is the required boiler output temperature, not the room temperature. To get this right, a simple PID control algorithm will do.

Good luck.

marcelr

[cagnulein]

Thanks marcelr, thanks for the clarification.
Just to be sure to understand what you said: you mean that the setpoint for the boiler should be different from the one used by the room. So for example, for rooms i need 20°C but the boiler temperature should be 35°C.
What i would like to do is to set the boiler temperature fixed all the time, and changing it when i will be away for a lot of days.

[marcelr]

That's similar to on/off control, only even more crude. It will give fluctuations in the room temperature, because of the temperature variations outside (and the corresponding variations in heat loss from your home).
If this is what you want to do, I would still keep my on/off thermostat in place, and limit the maximum boiler temperature (if that boiler allows this value to be set in its own software, most modern boilers do).

OT control is better in terms of temperature stability and gas consumption. So, if you can get your hands on a cheap OT compatible thermostat, I would go for that.

<commercial break>
I'm not sure where you live, in The Netherlands, Eneco has introduced a newer version of their smart thermostat Toon, the old types are available second hand at dump prices. For thermostat use,the old type is just fine, and you should be able to get one for EUR 30,-- or thereabouts. Extended support for this thermostat is available from this forum.
</commercial break>

[cagnulein]

If this is what you want to do, I would still keep my on/off thermostat in place, and limit the maximum boiler temperature (if that boiler allows this value to be set in its own software, most modern boilers do).

It's exaclty what i would like to do. So i would like to keep my thermostats adding the ability to write the value on the boiler via OTGW.

OT control is better in terms of temperature stability and gas consumption. So, if you can get your hands on a cheap OT compatible thermostat, I would go for that.

Yes, a simple OT thermostat should be enough but i need to set the temperature remotely (i don't know any OT thermostat that works via wifi) and reading values from the boiler as "nice to have"

<commercial break>
I'm not sure where you live, in The Netherlands, Eneco has introduced a newer version of their smart thermostat Toon, the old types are available second hand at dump prices. For thermostat use,the old type is just fine, and you should be able to get one for EUR 30,-- or thereabouts. Extended support for this thermostat is available from this forum.
</commercial break>

I live in italy. You mean this one https://www.toon.eu/toon-2 ? It's OT? I can't see OT in its specs

Thanks again for your help!

[marcelr]

I live in italy. You mean this one https://www.toon.eu/toon-2 ? It's OT? I can't see OT in its specs

Thanks again for your help!

That's the new type, the old one is a bit more square (and has less processing power, but enough to be used as a thermostat). It has OT support, provided through an intermediate box which also acts as the power supply.
For more info, just check out the toon thermostat subforum here. In the rooted version, we implemented a vnc client such that you can operate the thermostat from your phone. I think it supports Italian, but I'm not entirely sure.

[cagnulein]

English will be fine too. I can't understand where I can buy it and the intermediate box: is there a store or something?

[marcelr]

They are only sold with a subscription included. Brand new ones are quite expensive, you should get a second -hand one from this Dutch site:

https://www.marktplaats.nl/z.html?query ... distance=0

(only in Dutch, I'm afraid, but Google translate may help a little).
For external access it needs to be rooted. We can help you with that.