How to control a Vaillant boiler with a HMiP WHS2

[kenjiru]

Hello,

I have an underfloor heating system with a Vaillant ecoCOMPACT VSC 206/4-5 90 boiler with a multiMATIC 700 module. Currently the boiler is programmed by the multiMATIC 700 module to provide heating and hot water on a weekly schedule (day/night time tables).

For the automation part there is an HMiP Access Point, 2x HMiP Floor Heating Actuators (12 channels, motorized) and a bunch of wireless thermostats. The system is working fine like this. The only issue is that the boiler fires up even when all the rooms already reached the desired temperatures. This happens more often lately as the days get warmer.

To try to fix this issue, I've added a HMiP WHS2 module. I've connected the OUT (1) of the HMiP WHS2 module to the 24V=RT connector on the boiler motherboard, which I read online that it can be used by thermostats to control the boiler. In the instructions manual of theHMiP WHS2 module, is written that OUT (1) is the recommended port to connect a boiler.

In the mobile application, I've configured the HMiP WHS2 module to allocate the following function *Heating and cooling demand control for floor heating actuators*.

I've attached a series of pictures with my configuration.

Now I have a few questions:
* is the OUT (1) port the best port for controlling the boiler?
* is the *Heating and cooling demand control for floor heating actuators* the correct function?
* what does the light bulb symbol next to the switch actuator mean?
* how can I debug if this configuration works as expected?

[tomi_cc16]

I dont have a WHS2 but just for your info there are alone many posts in the English section that you can check for more information:
search.php?keywords=WHS2&terms=all&auth ... bmit=Suche

[kenjiru]

Thanks tomi, thanks for your quick reply. I've already searched the English forum about this topic. Most of the topics are about systems with radiators, for which HMiP WHS2 offers different options. Maybe CCU3 offers more options for debugging, but I would like to know more opinions before going into this direction.

The most useful comment so far I found to be this one (I think the Channel 2 is wrong labeled there):
viewtopic.php?f=49&t=44824&start=20#p495122

[tomi_cc16]

You can try to write to Doctor.ventil or Sergo a PN (Private Note) if they are not looking constantly in the forum

Also in parallel you can ask the eq3 support and post their answer here as the WHS2 is not so common yet.

Contact eQ3: support@eq-3.de
https://www.eq-3.com/service/support.html

[Doctor.ventil]

Hi Kenjiru.

I am a very basic user, so I can answer only few things...

I also use port OUT1 to switch on and off my electric boiler, but I have only (14) radiators with eTRV2 heads, quite an easy set up... and it works just briliant

I use only option called "heat demand for rooms"... but I don't have a floor heating like you as mentioned above...

Bulb means simply WHS2 is activated based on demand from some Homematic IP element... it is a symbol to show it is "ON"

[Vincentj94]

Hi Kenjiru,

Did you ever managed to solve this issue? I'm getting a similar problem with the WHS2 (but opposite, not always firing on when it should). Just curious what your experience was.

Thank you!

Kind regards,
Vincent