The Efficient Home Forum

I have just installed my second EvoHome system. I left the first system when i moved house and have just added EvoHome as my preferred smart heating solution.

My question is based around the OpenTherm Bridge, i have installed the whole house setup with a new wifi controller, 12 HR92 and 4 HR91 radiator valves and a BDR91 relay to enable the boiler.

I then found my boiler (Ideal Logic ESP1 35) had connectivity for the OpenTherm module, so i have now added that to the system.

I expected to have to remove the original BDR91 but on testing the BDR91 still operated and seems to be the main call for heat after the request from any radiator valve, even though i have paired and set the EvoHome controller to the new OpenTherm Bridge.
Should i remove the BDR91 and just short out the 'thermostat' control signal to the boiler and leave all control to the OpenTherm Bridge or should i leave the BDR91 relay in the system just purely triggering the boiler for fine control by the OpenTherm unit?

Thank you in advance.

Darren

The OpenTherm Bridge should be the only item that has a heat demand for the boiler and the BDR91 needs to go.

If you have Hot Water priority enabled in the Evohome controller, this only works where there are motorised valves on both Hot water and heating. If you remove the BRD91 that controls the Heating motorised valve, Hot water priority will no longer work. So, my question is, can you leave the BDR91 in place to control the heating valve and let the Opentherm bridge control the boiler or is DHW priority incompatible with an Opentherm system?

Personally I would convert the system to PDHW using X Plan and get rid of the heating BDR91 as above.

Thanks Richard, do you know if Honeywell have considered changing the firmware so that all HR92's close when HW priority is requested by the controller? That would mean a NO valve would not be needed in the heating circuit.