Viessmann Vitodens 200 with Tado

I have a Viessmann Vitodens 200 with weather compensation controller.
The weather compensation is ok, but I wanted a way to give feedback to the boiler based on the actual temperature of the house, for example to put more heat in if a door had been left open.

I went for Tado after seeing it advertised on the Viessmann website and checking with both Tado and Viessmann that the system would be compatible. I liked the geo-fencing function so the house would only be heated when we were home. The thermostat is meant to compliment the weather compensation by providing a 20% room influence.

Since installing Tado the boiler had been behaving strangely. There have been many error codes which seems to have been resolved by a firmware update. However whenever the Tado calls for heat it seems to do it excessively. The boiler ramped up to 69 degrees and 81% output just to raise the temperature by 1 degree. The dial on the gas meter was spinning! Additionally today when I came home the frost protection symbol was being displayed on the boiler despite the weather compensation sensor registering 12 degrees.

I just wondered if anyone else had experience of using Tado with a Viessmann 200 and if so have you had / resolved any similar issues?

Thanks

Has there been any progress with this?

Hi,

I’ve had many emails and support calls with Tado. They have had me change various parameters in the boiler, which has cured the error codes and got the boiler performing consistently. I think part of the issue is that the Tado thermostat makes the boiler behave very differently to how the weather compensation system alone works. The weather compensation would heat the house quite slowly and tick over at a low temperature whereas now the house heats much quicker and the heating then goes off when up to temperature.

I have had the frost protection come on a couple of times when not needed. When I’ve noticed I’ve turned the boiler off and on again, which sorts the problem.

Overall I’m happy with how it is working, now I’ve got used to it. I don’t think we’ll make any gas savings though!

I’m having a new viessmann 222-f installed replacing an old vented system that I had setup with Tado and was planning on keeping it. My plumber knows viessmanns inside out and said it’s not possible to use Tado and continue to use weather compensation as Tado basically takes over. Sadly I’ll be selling my Tado v3 room Stat.
For me the Tado gives good control over individual rooms so I’m going to invest in the Tado TRVs for controlling rooms that we don’t use regularly and bedrooms we want to keep a bit cooler. These don’t need any integration with the boiler itself so keeps it simple.

I understand what your plumber is saying about it taking over. The systems are meant to compliment each other and Viessmann even promote Tado on their website and you can buy the Tado system in a Viessmann branded box!

As far as I could work out from speaking to Viessmann about how the systems work together: the weather compensation is used to set the flow temperature of the boiler whilst the Tado thermostat sets the demand based on the room temperature. In practice this is not the case, as when Tado sends demand for heat the boiler fires at full whack and continues to do so until the set temperature is reached.

I don’t have the Tado TRVs but from what I have read they seem good and I may invest in some of them in the future.

Hi there

I am a Viessmann Installer

Tado is a way viessmann have used to make their Vitodens 100 app ready

You can use it on the Vitodens 200 but it’s better using the HO2B or HO2C and getting their Vitoconnect

Tado works using Opentherm which will run the boiler at a higher temperature then modulate the burner once the temperature nears its target. Weather compensation is better on the 200 due it’s modulation capability

The 222F will work as someone mentioned one, it just won’t be able to control the hot water.

Update - I received the following from Tado support;

The Viessmann Vitodens 222-F BT2B boiler is usually controlled by the fit-in controller called Viessmann Vitotronic 200. Outdoor temperature sensor transfers the outdoor temperature to the controller which then determines the heating demand.

When you connect tado°, it transfers the set point room temperature and current room temperature to the controller which then determines the heating demand.

The resulting heating demand is determined by the Vitotronic controller and based on the controller parameters. When tado° is connected, the following parameters are set:

• Time constant for calculating the adjusted outside temperature (parameter 90): 12
• Remote Detection (parameter A0): 1
• Room Temperature Hook-up (parameter b0): 3
• Room Influence Factor (parameter b2): 64
• Saving Function Room Temperature (parameter b5): 5
• Increase of the set flow temperature (parameter FA): 0

The Outdoor Temperature Influence, as you can see, is not modified and stays at the same level as before installing tado°.

*Exact parameters might vary depending on the model of the Vitotronic 200 controller.

I have a Viessmann 222 with weather comp and Tado across rads and 10 zones and have experimented with pretty much every config I can think of between the two.
In pretty much every scenario, the digital connection between the Tado and the viessmann heats the house faster but uses considerably more gas. It pushes the boiler to peak temp (capped at 65 on mine) and stays there until the room in question gets to temp.
It’s responsive, but expensive to run, with little regard for flue efficiencies and condensing.

Where I’ve ended up is letting the viessmann do the weather comp and just have the Tado on relay (which only opens the valve for the underfloor heating in the kitchen, the other valve is now jammed open). The curve is set to 1.7, 7 and I use set back from 10am to 5pm and 10pm to 530am. I also have 10pc overload for 1 hour on switchover from set back to normal.

This combination keeps the house warm all the time (we have 2 kids and a nanny so there is someone in the house all the time mostly) and on the rare occasions where we want the house a bit warmer in the day, we just boost the boiler for an hour in comfort mode.

This combination keeps all the rooms warm (bedrooms at 15deg overnight) and uses about half the gas Tado does. I swap it between one setting and the other every month or so just to check, and it’s consistently between 1/3 and 1/2 of Tado. My last check was yesterday.

We use Tado away etc when we are all out of the house, but with the valves reduced on the rads, the hot water temp coming back into the boiler is not much off what it’s sending out so it seems to stay low.

I’d love to know if anyone has found Tado ‘s software to be better, I’d love to be able to use the Tado as a simple (dumb) room stat to effectively tell the boiler when it’s not needed at all on sunny but cold days where our big windows warm the house very well.

If you want it as a dumb stat your better off getting a Viessmann Vitotrol 200 and using that with internal reference, then use the tado to control over shoot or keeping rooms cooler that aren’t used. Let the boiler do the WC and let it modulate

Quite possibly...it’s more a question at this point of trying not to add more kit to the equation...
I’m sure I must be able to configure the tados to do this

I don’t think so if I am honest

Install Guide

https://www.scribd.com/document/408271090/Smart-Thermostat-Installation-OpenTherm-KMBus