If you are operating your Honeywell Home evohome and using it in S or Y Plan configuration (as per Pages 42 - 45 of the evohome Installation guide - https://digitalassets.resideo.com/damro ... 1-uk01.pdf) then you probably don't have a BDR91 setup as a 'Boiler Relay'. The only time we normally use a BDR91 as a 'Boiler Relay' is when you have evohome fitted to a Combi Boiler, or setup as a 'Figure 4' system (Page 41 & 46 of the evohome Installation Guide).
Therefore, in order to stop this message occurring you need to press & hold the 'SETTINGS' button for 3+ seconds, then go to 'INSTALLATION MENU' > 'BOILER/APPLIANCE CONTROL' > 'NONE' and press the GREEN TICK. This will stop evohome thinking it has a 'Boiler Relay' when one isn't present.
I hope that helps and for further technical information on evohome system setup, contact Resideo on 0300 130 1299
