Heating system, valves and turn the central heater on


I’m setting up a heating system.

I have a termostat in every room. Every room has is own circuit of radiators with a valve.
I can control with the thermostat the valve. But would it be possible, that if the valve is open and asking for hot water to turn the central heating system on, and also off if all valves are closed ?

Best regards


The central heating has an on/off with a normal thermalturndisc or something like that?

A normal/old on/off C.V. can be turned on and off through a for example Fibaro Smart implant.
You can use an output from that to switch the C.V. Connection.

If you have opentherm in stead of on/off, I suppose it would be possible, but you would need some converters.

In addition: can you Homey allready know if a radiator/valve has been turned on?
If so, easy.

If not, you would need a waterflowmeter connected to the outlet pipe next tot your C.V. and connect that (with the same smart implant) to your Homey.

Hi Arie,

I can use the On/off or with an KNX module. So for now I can use the On/Off.

But is it possible to config this by a flow, so if one of more valves are asking for heat that the CV goes ON. And it if none of them are asking heat, that the CV goes out. Or do i need Scripting, i’m new to this so I’ve only used small flows.

Well the question is, does Homey get a signal that the valves are opened or that the radiatorthermostats are requesting heat?

If you have the radiators (or valves) connected to Homey as some kind of devices, then i would advise using the app Group to group all vales/radiators together and then you can use the group triggers.
You would only need two flows (or perhaps even just one):
One when the group requests valves open or heating then send On to the Relay within a Smart Implant.
And another for when all devies in the group are not requesting heat/open valves, then send Off.

But it all depends on if and how the radiators are connected to Homey.


They will all be contected, with a Heat-IT relay and Heat-IT Thermostat.
So normally i can controll it all in Homey.

Do you know a good heating App of Plugin ? I’m comming from a Fibaro HC2 and there was a special Application for this.

Thanks for the Help/Advice !

No i use HoneyWell which has it own way/App of working.
But if you just want to on/of your C.V. then, like i said, i would use the <Group> App.
You create a new device, select all radiators and now you can create a flow that triggers from actions within that group.

So one group with all radiator in it and you use the trigger from that group as trigger, and use a smart implant’s relay to start the C.V. and shut it down.

Thats it.


This worked great for a week. When a Temperature sensor of Heat-It was under the requested temperature a valve opent and also the pump started. I also made a flow when the temperature dropped in our buffertank that the Heater started to warm up the tank again.

But suddenly most of the valves stopped working. I don’t think that it’s Z-Wave reception related.
Because the valve is also opened in Homey itself.
I tried to make changes in delay, but that didn’t help.

Any suggestions ?

Best regards

If the heater is opentherm you can buy an opentherm gateway. Install the otgw homey app.
And start controlling your heater…

But make sure to have a shortcut in your heating system.
You dont want to overheat the heater when you make a mistake in your flows and all vlaves are shut and you heater start up…

Hi Jan
This is what I done I’m sure it can be simplified
Two screenshots needed So just take up from where needed on second screenshot