I am nowhere closer to figuring out what is causing that oscillating temperatures for the Child Bed and Lounge zones. I've added the unused sensor but strangely there is no unused sensor added for the Child Bed zone with the issue, when I expected one. I'm not using the radiator sensor but a T87RF sensor, so expected the radiator sensor to be picked up, but it hasn't even after multiple reboots.
Three zones where unused sensors have been added, don't actually have any unused sensors! because the radiator controller is acting as both the sensor and the actuator.
And then lastly I have these two Zone 1 sensors that don't appear to resemble anything from my house, yet they are active. One changed from 10.7 to 10.9. The other has stayed at 0.0 for hours. The only thing that leads me to think this has got something to do with my installation is because these two sensors have the same ID as 2 of the 5 relays that we auto detected by Domiticz but have always stayed with a value of 200, so I didn't bother tracking them.
33 myEvohome 581a20 0 Zone Heating Relay On: 200 - - Add DeviceRename Device 2016-11-13 09:30:45
34 myEvohome 58d675 0 Zone Heating Relay On: 200 - - Add DeviceRename Device 2016-12-10 01:04:09
32 myEvohome 58d723 0 Zone Heating Relay On: 200 - - Add DeviceRename Device 2016-12-13 17:30:22
62 myEvohome 58d723 13 Zone 1 Heating Zone 0.0 C, (22.0 C), Auto - - Set UnusedRename Device 2016-12-13 19:29:21
35 myEvohome 590a35 0 Zone Heating Relay On: 200 - - Add DeviceRename Device 2016-11-19 11:23:30
24 myEvohome 590a3a 0 Zone Heating Relay On: 200 - - Add DeviceRename Device 2016-12-13 20:22:05
61 myEvohome 590a3a 13 Zone 1 Heating Zone 10.9 C, (22.0 C), Auto - - Set UnusedRename Device 2016-12-13 20:11:01
Plotting all the other sensors against the zones that oscillate also doesn't reveal anything because I can't find another zone that correlates to the bottom end of the deviation.
Looks like I'm going to have to build a Pi and get the Domoticz running in debug mode on it to work out what is going on here.