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Custom zone control

PostPosted: Wed Jan 30, 2019 3:12 pm
by Luc_S
Hi all,

I need some help regarding a custom zone implementation. My problem is pretty common: Downstairs I have heated floors and upstairs radiators all in 1 circuit. The houses' insulation is good which causes our bathroom upstairs to be kinda chilly these days (mechanical ventilation on lowest setting pulls out the warm air in a few hours but downstairs stays on temperature way longer). Climate is controlled by a rooted Toon 1 using OpenTherm located downstairs.

With some parts laying around I was hoping to fix this by;
    1. Adding a temperature sensor in the bathroom
    2. Adding a KlikAanKlikUit switch to my floor pump. With this turned off it would prevent heating downstairs when only upstairs is chilly. It also reduces the impact on Toons' learning curve.
    3. Somehow ask my CV to start heating up the house when Toon is on idle but bathroom is getting too cold.
    4. Somehow know when Toon kicks in during a "only-heat-upstairs" cycle. (to turn on the floor pump again)

So I got to work last weekend:
1. Check
2. Check
3. Sadly my CV doesn't allow for a second on/off thermostat (relay) next to one operating with OpenTherm, this would have been ideal to implement number 3.
4. I guess Toons "boilerInfo" parameter can be used?

To implement number 3 I'm now searching for a way to start the CV through Toon but with fully bypassing all of its functions. If I simply increase the target temperature of Toon, there's no way of implementing no. 4. Also with the floor pump turned off and Toon asking loads of heat without sensing any temperature increase, wouldn't it mess up Toon's learning curve? Are there any background parameters/services on the Toon which I can use to start the heating process?

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 3:18 pm
by TheHogNL
You need to disconnect your toon from the cv ketel and put a system in between.
So Toon triggers the system and the system triggers the boiler.
If you want to keep opentherm, you need to buy the opentherm gateway.
But I would advice to try with aan/uit first, which makes your setup much easier. The intermediate system could then just be a simple ESP8266 with some arduino code or a raspberry pi with domoticz and some code checking the pins.

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 3:39 pm
by Luc_S
I have an OpenTherm gateway somewhere but I think I broke it while connecting the Toon :P Maybe I can revive it.

I am afraid the on/off solution would increase my gas usage more than I would want. I'm already going to use more when heating up my bathroom :) Is there a known estimate in percentage that on/off is less economical then OpenTherm?

I will try to setup this on/off solution tonight, I have a relay already configured and hooked up to a rPi :D (but then I noticed it didn't work with OpenTherm :lol: )

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 3:47 pm
by TheHogNL
With on/off just put your boiler on max. 60 degrees and the loss is not that big. Sometimes even better because with opentherm often the requested water temperature is too low causing the boiler to continu switch on and off.
The toon has the habbit, with opentherm, to request a too low water temperature (around 30-35 degrees) when room temperature is near setpoint. This is ok for your floor, but not good for your radiators which can not do anything with that relative cold water.

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 4:28 pm
by Luc_S
Ok sounds good, I'm very curious about what it will do in my situation. I'll keep you posted :D

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 4:54 pm
by TheHogNL
Luc_S wrote:I will try to setup this on/off solution tonight, I have a relay already configured and hooked up to a rPi :D (but then I noticed it didn't work with OpenTherm :lol: )


Your setup would be to hook the relay to the boiler (on the on/off connection indeed, sometimes the same as the opentherm connection). Then switch this relay in your raspberry on request (when temperatures upstairs is too low or when the toon is requesting heat).

To check if your toon is requesting heat you can indeed monitor burnerInfo from the well known URL /happ_thermstat?action=getThermostatInfo
Or you could hook your toon ketelmodule to a digital input of the Pi (and with a hardwired or software pull-up/down resistor).

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 5:01 pm
by TheHogNL
Also don't forget when you disable the floor pump the warm water is still flowing through the floor distributor. The heat is only not being transfered to the floor system itself. Therefore the water coming back to the CV ketel is not cooled down by the floor system (only by the radiators upstairs). This could affect the boiler to go into standby mode to ofter because the return water temperature is too high. If this becomes an issue you should install a 2-way valve in front of the floor system also.

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 5:22 pm
by Luc_S
That's a good point. This 'issue' you speak of, is that a boiler error? Or just that it's switching too often and if I find this annoying I could add a valve?

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 5:51 pm
by TheHogNL
That is called 'pendelen' in Dutch. The boiler stops producing warm water if the return is at or near the requested hot water temperature. Normally this should not occur because the water is always cooled down at the radiators.

In your case, lets say 50% is going to the radiators and 50% is going to the floor distributor. When 60 degrees hot water is requested, 50% will be cooled down to lets say 40 degrees by the radiators upstairs. But the floor distributor is not cooling the water, only for a few degrees but lets keep 60 degrees just to calculate easier.
This means that the return water would be around 50 degrees at first but when the radiators are warming up this slowly increases to around 60 and the boiler stops.

You could also squeeze the water flow in the floor distributor a bit (at the return side there is probably a screw/minivalve which allows you to squeeze the return flow). This will also affect the heat delivery to the floor when the floor does need to be heated though. Fine tuning is key here. Idealy the return temperature from the floor distributor is just one ore two degrees higher than the return of all different water pipes going back from the floor.

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 6:15 pm
by Luc_S
Ah ok. Thanks for explaining.

That last part is about 'waterzijdig inregelen' am I right? I'm going to read up into that too for finetuning.

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 6:43 pm
by TheHogNL
Correct

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 9:47 pm
by Luc_S
Alright, got it all up and running. Before configuring the automated heating using the relay I first want to let it run on aan/uit for a day. Should I reset Toon or remove the self-learning info he has stored somewhere now I got it hooked up as a aan/uit thermostat?

Re: Custom zone control

PostPosted: Wed Jan 30, 2019 9:50 pm
by Akatar
TheHogNL wrote:You need to disconnect your toon from the cv ketel and put a system in between.
So Toon triggers the system and the system triggers the boiler.
If you want to keep opentherm, you need to buy the opentherm gateway.
But I would advice to try with aan/uit first, which makes your setup much easier. The intermediate system could then just be a simple ESP8266 with some arduino code or a raspberry pi with domoticz and some code checking the pins.


the system in between can maybe a plugwise adam,
as far as i know the toon will be zone 1 and you can add tom's an lisa's to create more zones

not sure though