HCC80 issue?

[paulh]

We've had Evohome for about 7 years and has been working fine but lately, the UFH (HCC80) has not been heating one room to the correct temperature (all the other UFH zones and rads are working fine). I bought a RAMSES_ESP so that I could look at what was happening in more detail and found that when the temp of the room was less than 1.5 degrees below target (and demand was down to 30%), the actuator was going on and off every couple of minutes but the boiler was being fired up every couple of minutes but the two didn't necessarily coincide so the UFH was pumping around lukewarm water part of the time. Has anyone else seen this issue? I've attached a picture of the graphs.

Resideo asked me to rebind the system which I did but no difference. They are now saying that I need to replace the HCC80 which seems a bit strange as I thought that the evohome controller would control the firing of he boiler and not the HCC80.

Has anyone else seen this issue?

Thanks,
Paul

The system is as follows:
Evohome controller – ATC928G3000, App software version 02.01.01.01, wifi software version 02.00.20.00
10 Radiators with HR92s in 8 rooms (i.e. 2 rooms have 2 radiators). This was originally setup with a zone valve just this is now permanently open
Hot Water cylinder with valve and thermostat
UFH controller (HCC80R version 1.04) with 3 zones. Zone 1 has 2 actuators feeding 2 loops, zone 2 & 3 have 1 actuator/ loop each. Each zone has a thermostat (DTS92).