About This File
I have a number of Danfoss LC-13 valves around the house, together with a Secure SSR302 to turn the boiler on and off. The Danfoss valves are controlled by the Heating Panels, and I also have a Fibaro multi-sensor in each room. I've noticed from a number of posts on the forum that there are other people with the same or similar setup, and need a scene to control the boiler switch. The idea being that if any room needs heat, then the boiler will be turned on, and once all the rooms have reached the required temperature, then the boiler will be turned off.
Setup required:
Modify the device id for the Secure SSR302 (or whatever device is used to control the boiler) here:
local boilerSwitch = 84
You might also want to tweak this value:
local threshold = 0.3
This is used to build in some hysteresis into the system to prevent the boiler from being switched on and off too frequently. The boiler won't switch on until the temperature has dropped below the target temperature by this value or more.
The scene is triggered by a global 'timer' variable to run every 5 minutes. There are a number of timer scenes on the forum, but this is the scene that I use.
You should also change your Danfoss valves so that the Wake Up Interval is 300 seconds. I find that this doesn't have a detrimental effect on the battery but allows the devices to respond more quickly to the temperature change requests.
The scene works off the temperature sensor and thermostat that have been defined in your Room settings, so ensure that these are correct:
Note that this method of controlling the boiler assumes that your temperature sensors are working to the same temperatures as your Danfoss valves - ie: the Danfoss valves turn off once they've reached the target temperature, and that the temperature sensors are also reading this same value. You may need to tweak the temperature offset for the temperature sensors so that the two devices are in sync with each other. If in doubt then set the temperature offset so that the sensors read a slightly higher temperature. That way, the scene will think that the room has reached the desired temperature and turn off the boiler. Otherwise you may find that the boiler is not switching off because the room has reached the target temperature, but the Danfoss valve has already turned itself off.
Other types of boiler switch might not use the 'mode' property to determine whether they are on or off. Consequently, the following line may need to be changed, for example to use the 'value' property instead of 'mode':
local boilerOn = (fibaro:getValue(boilerSwitch, "mode") == "1")
Side topic:
Note that there is a school of thought that boilers should be left on all the time even if there aren't any rooms that require the heat, and that the boiler's control logic will detect this and modulate the water temperature accordingly. I don't necessarily uphold this view, but then I'm not a heating engineer either, so I'm happy to be persuaded either way. In my case, I believe that my condensing boiler operates most efficiently when there is a 20C difference between the output and input water temperatures, and as a result it needs the radiators to be drawing heat from the system. I also have radiators that aren't controlled by Danfoss valves (bathrooms and other small rooms), and I don't want to be heating them all the time, wasting energy. After all, the whole point of the Danfoss valves is to avoid having to heat rooms that you're not using, and thereby save some money. Maybe the more intelligent boilers that can regulate the water temperature according to the system's needs and outside temperature operate differently, and as a result more efficiently, and can be left on all the time. The general opinion, in the UK at least, appears to be that the heating should be turned off if not needed. Just my tuppence worth, but I know that views like this can be contentious so please don't shoot me down in flames.
As another side topic, it looks as though the new Fibaro TRVs are far superior to the Danfoss TRVs with the built in algorithms and the ability to cooperate with another sensor in the room. They should certainly avoid a lot of the problems that we get with the Danfoss valves. Pity I can't justify replacing them.
What's New in Version 1.1.0 See changelog
Released
The scene can fail if a non-thermostat or non-thermometer device is selected in the room properties. Additional checks have been added to ensure that the device has the correct properties.