Note: YMMV! Please update anything that you think could be corrected / improved.

This is a HA custom integration that works with some Honeywell RF-based systems such as Evohome, Sundial, Hometronic, and many others.

HVAC systems from Orcon, Nuaire, Vasco, ClimaRad and Itho Daalderop are also known to use the RAMSES II protocol.

Note:

Ramses RF can not interpret the new Honeywell Ramses-III (R3) messages used after a firmware upgrade since 2025 and (some) new devices.

The Ramses RF integration requires a serial-to-RF gateway device connect to a RAMSES control system. Options include:

• a Honeywell HGI80 (rare, expensive)
• a USB dongle running
  • ramses_esp (more features, recommended) or
  • evofw3 (predecessor)
• Another product designed for this purpose
• DIY solutions based on the ESP3S CPU

This Wiki does not cover installing and configuring hardware, see the ramses_esp Wiki for more on that. Set up your gateway according to the manufacturer's instructions, then return here to use the hardware as a bridge between the climate devices and Home Assistant.

Ramses RF uses the ramses_rf client library to decode the RAMSES II (Room Apartment Manager System Engineering Specification) protocol used by these devices. Note that other systems, such as HVAC, also use this protocol but adapt it a bit so YMMV.

The forum for help/support/feedback is: https://community.home-assistant.io/t/honeywell-evohome-via-rf-hgi80-hgs80/151584 The GitHub repository Issues are NOT to be used for support question ('how do I ...). Study this Wiki in full, study the code and head over to the user forums where you read a lot, before asking for help.

For CH/DHW-based systems, the simplest way to know if it will work with your (868 MHz-based) system is to identify the box connected to your heat source equivalent to one of (there will be other systems that also work):

• R8810A: OpenTherm Bridge
• BDR91A: Wireless Relay
• HC60NG: Wireless Relay (older hardware version)

For HVAC systems, anything based upon an Airios chip will do. Functions available inside the Ramses RF integrations depend on the device, and range from very basic to full control and measurements.