Itho / Orco / Nuaire: Fan metrics, Remote control & Sensor faking via RF

The evohome_rf custom integration has morphed into ramses_rf and now supports HVAC in addition to CH/DHW at a relatively mature level:

I feel is worth announcing in a separate thread, to increase the visibility of this project for HVAC people.

This means, for ventilation units compatible with Itho / Orco / Nuaire RF-based systems (HRUs, CVEs, & PIVs) using the RAMSES_II protocol, you can:

  • monitor ventilation unit metrics, e.g. fan speed, air flow rate, fan mode, CO2 level, humidity, etc.
  • fake CO2 / humidity sensors (other sensors coming soon, e.g. PIR) with any HA-aware sensor
  • control ventilation remotes: mode (.e.g. speed, auto, away, etc.), bypass mode, etc.

For this integration, you’ll need a USB dongle running evofw3, such as this one (you can make them yourself, or source them elsewhere).

Photos coming!


I am currently running the latest master. Works really well. My overview to control the fan:
and the CO2 overview (with entity names removed):

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Here you see the automatic bypass of an Orcon HRU in action, first image is the measured air flow, second one some temperatures (all taken from the HRU):

To add to the nice graphs:
A graph showing supply flow (in wrong units, fixed in the latest release) and CO2 level of the CO2 remote driving the fan. Note the heavy oscillations. I’m working on fixing this, but these graphs help a lot!

The square wave around 18:00 is from using setting 3 (1 hour max flow) for cooking. Around 23:00 we when to bed and the CO2 starts rising.

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I am thinking of adding probing - the system eavesdrops, and picks up fans/remotes/sensors (you can facilitate this by pushing buttons on your remote) - then probing the fan to:

  • determine if Orcon, Itho or Nuaire scheme
  • determine modes supported by the ventilation unit
  • automatically adding those modes to either a Remote / Fan or HVAC entity (I haven’t decided yet, which)

The issue here is that the probing will make the ventilation (e.g.) change fan speed, etc. - so would best be a service call?


If I understand you correctly, you want to ask the user to do a single button press, and then probe the addressed fan with all known commands for the detected fan scheme by impersonating the remote?

Can’t you determine the model of the remote, sensor or fan based on their ID packets, and derive the supported commands from them? That feels safer… but it does add the burden of managing some sort of capabilities database to the software.

So I have a Nuaire PIV Eco-Dri system. if I was to set this up how do I get it to start listening in on the RF signals. do I set it to a pairing mode for the button units? I have wanted to be able to control this unit remotely for ages.

See posts above. They failed to get this working only because their PIV did not support RF.

If the PIV does support PIV then this is doable

  • it will listen/discover the FAN by default
  • you will have to create (and likely bind) a faked remote

I believe you are referring to the other thread, here.

My understanding is it does support RF as it can take the RF remotes 2 and 4 way. just wanted to know how it then discovers the fake remote.

What you want should be straight-forward.

I have a Nuaire 4-way connected to my PIV that I bound years ago. Relatively recently, I have been simply impersonating that 4-way with a faked remote.

The RF dongle you require will be a lot cheaper that the 4-way switch, and you have the added advantage of HA sensors, etc.

You will have to do the binding with the faked remote - you put the PIV in binding mode and press/hold boost on the 4-way - you do that via HA service call.

You’ll need to edit the configuration.yaml file too.

All the code for the above is in place, although if there is a problem, I can look at it for you.

There is no reason why ramses_cc can’t be used to impersonate a humidity sensor too - although this is a WIP - it would be eaiser to use an automation to trigger a boost when a humidity sensor rises above a set level.

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Thanks for that. sounds great. as you say going to be alot cheaper than a £90 4 Way and I get HA Automation, remote access to it ETC.

Any recommendations for the right RF sensor options available in the UK? the one linked is out of stock. I can then get this setup and working.


Perhaps ask on the other thread: Honeywell CH/DHW via RF - evohome, sundial, hometronics, chronotherm - Share your Projects! - Home Assistant Community (