The Efficient Home Forum

Hi,
Im new. And I want to change the bosch greenstar system boiler control to opentherm. So I need easycontrol bosh adapter and Honeywell Home R8810A101. I remove the R8810 and turn the pump on permanently? And that's all?

Thanks

Easycontrol unfortunately isn't built to convert Opentherm to EMS, its built to covert EMS to OpenTherm.

There are Netfit adaptors you can buy from the Netherlands, but I haven't personally tried them.

Ok thank you for your reply

Hi,

Did someone try the Nefit adaptor with Bosch/Buderus EMS?

I can't answer your question, but can share a little more information based upon my recent experience. I've just had a Worcester Bosch Greenstar 30i Compact System boiler installed and based on the experience of other users I've added the 'Bosch/Nefit OpenTherm Converter EMS 1' (7746901847) and it's all working OK with my Evohome system via the R8810 OpenTherm Bridge. As you'll see from its description the Bosch/Nefit converter is designed to work with boilers which use EMS version 1. If you're able to find out which version of EMS your boiler uses (there seem to be many versions; EMS1 EMS2 EMS+ and others) it should give you more confidence of whether the converter is suitable for your boiler. I've had a search around, but unfortunately I can't find any reference material which indicates the EMS version used by your Buderus boiler.

Dan

DanD wrote:Hi,

Did someone try the Nefit adaptor with Bosch/Buderus EMS?

I can't answer your question, but can share a little more information based upon my recent experience. I've just had a Worcester Bosch Greenstar 30i Compact System boiler installed and based on the experience of other users I've added the 'Bosch/Nefit OpenTherm Converter EMS 1' (7746901847) and it's all working OK with my Evohome system via the R8810 OpenTherm Bridge. As you'll see from its description the Bosch/Nefit converter is designed to work with boilers which use EMS version 1. If you're able to find out which version of EMS your boiler uses (there seem to be many versions; EMS1 EMS2 EMS+ and others) it should give you more confidence of whether the converter is suitable for your boiler. I've had a search around, but unfortunately I can't find any reference material which indicates the EMS version used by your Buderus boiler.

Dan

I have recently bought a Netfit adaptor but it is a 7746900496... Any idea what the differences are Dan?

I've had a search and found pictures of the Bosch 7746900496 opentherm converter & packaging and compared it to my 7746901847 version and the actual devices look identical. The only obvious difference is that mine is described as an 'Opentherm converter EMS 1' on its box whereas on your model's box it is just described as an 'Opentherm converter'. My guess is that they've simply updated the model number & description to make it clear that it's not intended for boilers with later EMS versions, but it's only a guess.

I live in Poland. I bought a Nefit EMS-OT Converter in the Netherlands.
It works perfectly with my Buderus Logamax plus GB072(K)V2 (EMS protocol communication, Bosch group).
To put it very simply, my configuration:
Honeywell Evohome -> Honeywell R8810A1018 -> Nefit EMS-OT -> Buderus boiler.