Migrating my heating from Access Point to CCU3

[wutr]

Following the latest glitch I encountered with my Homematic IP Access Point where it decided the PIN I setup was invalid and therefore I am unable to use the app on my new smartphone, I decided it is time to ditch the access point and app and finally start using the CCU3 that I've had lying around for a year.

I want to recreate the same functionality I have with the access point and I have the following devices:

e-TRV-B (x7)
e-TRV-2 (x3)
STHD (x3)
STH (x2)
WTH-2
WHS2

After some trial and error I worked out that in the CCU3 I need to use groups to replicate a lot of the work that in the Homematic App is achieved by creating a room.

I have moved some "rooms" and their devices from the Homematic App to the CCU3. Naff interface aside it seems I can use the automatically created virtual heating interface to do heating control for each room.

My question is: how do I get the WHS2 to turn on the central heating boiler using the CCU3? In the Homematic App (using the access point) it automatically recognises all rooms that have a heating device and switches the boiler on when a radiator valve opens a certain amount.

[tomi_cc16]

Check here to find WHS2 in EN part:
search.php?keywords=WHS2&terms=all&auth ... bmit=Suche

When I strated the translation the WHS2 was not out then - but I guess like chapter22 (sorry this chapter still has many grama errors)
WebUI English Manual - EN Version 0.4

Here some overview info:
viewtopic.php?f=49&t=41325
viewtopic.php?f=49&t=45485

And I like this from Sergo:
viewtopic.php?f=49&t=46514&start=40#p490260

[wutr]

I read sergos posts but am still not sure about whether or not I need to create a direct link or just put everything in one big group.

Grouping everything in one heating group seems odd to me as it'll create direct links between everything, right? I need to keep the physical rooms separate. I don't want to heat the kitchen unnecessarily when asking for an increased temperature in the bedroom.

Using the access point and app, when combining a thermostat (eg. STHD) with a few TRV-B the TRV's internal temperature sensor will be overridden by the thermostat's value. That in turn makes the TRVs open an equal amount so they are always in sync.

How do I find out what channel does what? I have looked at the 13000 page data point document but it's not very descriptive.

[tomi_cc16]

I don’t have a WHS2 but you can ask about WHS2+CCU3 the producer per email. - post later the answer here.

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

[wutr]

I have asked EQ-3 the question "Can you explain how I need to set up the WHS2 to work as it does in the access point?" and here's the reply (copy-paste from their email):

You have to create a program in the WebUI to control the WHS2. Attached you can find an example program.
It is nexessary to check all relevent thermostats. The valve openung is 0.00-1.00 (0%-100%). So 0.1 stands for 10%.
If any of the etrvs are opend for more then 10% the WHS2 will switch on. If all valve oenings are lower then 10%, the WHS2 will switch off.
Since we are currently missing a pattern from the WHS2, we simply used a different actuator as an example.

I have yet to try this. I can't disable my whole heating system right now as it's cold outside!

If you read this Sergo, would you be able to give some input?

[wutr]

It's still a work in progress, but I have found that setting up direct links between the wall thermostats (STHD, STH or WTH-2) and the switch actuator WHS2 doesn't work as expected.

If you only use one thermostat it's fine. However, as soon as multiple thermostats are directly connected to the WHS2 they override each other which leads to the WHS2 turning off shortly after switching on. I read in a post somewhere on this forum that the WHS2 doesn't receive a separate "Off" signal from a wall thermostat; it just checks if there is an "On" signal. Therefore if it polls one of the thermostats that's not requesting heat, it turns the WHS2 off again until it gets back around to the thermostat with the "On" signal.

For now I have set it up as suggested by EQ-3 and the basic functionality seems to work, but the actual temperature seems to overshoot the setpoint by quite a lot, so some fine tuning may be required.

[Ganfoud]

Hi
I have a question: what's the behaviour when you loose connection to the access point and/or CCU? are the thermostats still able to communicate directly with the actuator or does it have to go through the gateway?

[wutr]

Hi
I have a question: what's the behaviour when you loose connection to the access point and/or CCU? are the thermostats still able to communicate directly with the actuator or does it have to go through the gateway?

In my current setup (link) they won't be able to communicate directly with the WHS2, because the logic is on the CCU3.

If I recall correctly, the Access Point implementation of the WHS2 allowed you to choose from multiple options with regard to heating setup. One of which was "Heat demand with leading room". Now that I have started using the CCU3 I understand slightly better how that function using the Access Point would have worked; I think it makes *one* direct connection between a room thermostat of your choice and the WHS2. You can select which other rooms are allowed to ask for heat demand, and in my interpretation that is done by valve opening percentage only, regardless of whether another room thermostat is present.

There was also another configuration parameter called "Emergency mode" (or something similar). That would kick in if the connection to "the cloud" was lost. It would turn on the WHS2 for a configured amount of time, then switch it off again, then on again, etc... But that depends on the Access Point still being up, so that's no use to you.

From my experience the Access Point + WHS2 + Valves + Thermostats was only reliable if you set it up and didn't touch it. As soon as you would add or remove one of the devices involved the WHS2 would no longer turn on the boiler. I never figured out why. The only solution is a factory reset of the WHS2 (which doesn't take long).

I saw your post on the homeassistant forum and I think you might want to consider trying a hybrid between my current setup using valve opening percentages combined with one direct link (the "leading room"). Let us know the results!