Underfloor Heating Activating Heating Relay

[smartheatingsystems]

Has anyone come across this issue, or know the solution:

When activating any other floor heating zone from main base, mobile app, or the Honeywell DTS92, the zone light on the Honeywell UFH Controller HCC80R come on and within seconds, Heating relay(BDR91) get activated too without any demands from Rad Valves.

I've reset everything and repaired it all with success. But above issue still remains.

Systems Setup:

5 Zone on the HCC8OR
4 controls by DTS92
1 controls by the main base, ATP921R3100
Hot Water Kits
4 Radiator valves controls by relay BDR91

Boiler controlled by opentherm bridge R8810, connected to the boiler via VR33.

Been on the phone to Honeywell Technical, and been informed that this is normal as we are using the Opentherm Bridge. I find that hard to believe as I've got similar set up as above in few other properties with no issues at all.

Any help would be greatly appreciated.

[Richard]

If you have a BDR91 set up as a 'heating actuator' it will have demand whenever there is 'heating' demand from any heating zone...

[smartheatingsystems]

I do have a BDR91 set up as an actuator for the radiators valves.

Is there any way I can prevent this from happenening?

My issue is, the client does not have, and does not want Evohome Rad valves on bathroom radiators, and as the BDR91 is coming on, the towel rails are coming on.

He is happy to have them come on when a radiator demand heat, but not when UFH demand heat.

[Richard]

No sorry, this is the way the evohome system has been programmed by Honeywell...