Cooling from Evohome without BDR91T, possible?

[ej3359]

I replaced my boiler with a heat pump.
It will be connected to a 200L buffer
I also have an Evohome atc928g3000 controller for multiple HR92 pilots. The Evohome controller did not control my boiler (independent control based on outside temperature)

I don’t want to connect my Evohome controller to my heat pump because I’m afraid there will be too many on/off cycles.

On the other hand, I want to be able to use my Evohome controller to heat in winters but also to cool in summer.

How can I do this? My checker was purchased in 2019. Is it compatible?
Do I need to add a BDR91T (even without connecting it to a heat pump) to manage summer cooling?

Thank you for your help and advice

[Richard]

The cooling functionality is merely a BDR91T acting as a switch which activates the cooling function of the heat pump. This has to be a BDR91T and the heat pump must have the functionality of cooling.

As far as on off cycles go, when you setup a Heat Pump relay with a BDR91T, this is literally 1 cycle per hour, so in effect just a demand switch for the heat pump, rather than control of the heat input like we use on gas and oil boilers (which are typically oversized).

All evohome controllers dating back to September 2015 (ATC928G3000 under the front flap) can have update firmware for this functionality, you just need to contact Resideo (Honeywell Home) to get this pushed through to your device (0300 130 1299).

[Richard]

BDR91T's are available to buy here BTW - https://theevohomeshop.co.uk/product/ho ... dr91t1004/

[ej3359]

Thanks for your replies