Evohome HR91s not triggering boiler start

[Jeff1243]

Hello all,

I had eight HR91s installed last summer, and now it is winter I am spotting one or two issues with the system. I am hoping that someone here has seen the problem before.

All eight sensors appear to be correctly connected to the controller. I can see temperatures going up and down, when I ask for a temperature increase I can hear the valves opening. The issue is that two of the eight HR91s do not appear to communicate that need for heat to the boiler. I am not sure how that part of the communication works, but the situation is, if I ask for heating in the bedroom, the boiler comes on after a couple of minutes as expected, but if I ask for heating in the lounge or the kitchen in isolation, the radiator valves open, but no matter how long I wait (hours) the boiler does not come on. Currently the only way to heat either of these rooms is to trigger the boiler with a second room that is already the temperature I want to be even hotter, which is not fantastic from an efficiency perspective.

In an effort to diagnose the problem, I set up Homeassistant, which amongst other things logs some of the data from the evohome system, but that hasn't helped. All radiators appear to be showing the same info. All have "active_faults: []" which given it is on all eight, I assume means zero faults, and all say "is_available: true". Nothing shows up on the controller for any of the radiators as a fault.

Has anyone seen anything like this before, or have any ideas on what I can try to do to solve the problem?

Thanks

[Richard]

I have my evohome UFH system setup on my HA at home, but I've not seen a radiator controlled system on HA yet (must get around to setting one up at our unit).

Have you tried all the basic steps? Recalibration of the HR91's? evohome Controller battery fully charged and permanently docked in a location all devices can obtain correct data in and out from? Deleted the room zones, cleared all data from the HR91's and rebound the system one at a time (I would delete all zones and clear everything, then add one HR91 test it... Does it work? Yes add another zone, test it... Does it work? Yes, add another zone...).

Some HR91 details are on the bottom of this page - https://theevohomeshop.co.uk/content/11-evohome-help (I still need to get around to get the video made I had planned for HR91 diagnostics).

There is a video here on how to get the HR92 to calibrate correctly, but this is the same with the HR91's too - https://www.youtube.com/watch?v=kEAD-IkXRrY