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RMU-40 Room sensor emulation


H66 can emulate an installed NIBE RMU-40 room controller (pictured below) for heating circuit one.

This can be used to forward any Room temp from a sensor in your home automation to the pump controller. It saves some money and install hazzle not having to buy a sensor and you can manage the temp level as you like. Note that you have to build this forwarding automation yourself. Husdata has no instructions for that currently.


The solution has not been fully tested on all pump models and combinations but works so far for a number tested setups. Please provide feedback.

How it works.
When enabled, H66 will respond to the when EB100 asks dfor indoor temperature. This happen every few  seconds. If you change sensor-temperature via the H66 Web interface, MQTT or API, it will be sent to the Rego as new current indoor temperature.

Please note that:
At H66 boot up, the temp will default to 20c until updated from your automation or in web interface.

If the controller is not getting any RMU-40 update for some time it may show an alarm and temp will be blank in the house icon on the display (if H66 is disconnected). The alarm is for Info only and will not stop pump operations. H66 will automatically clear the alarm when operatoin. To avoid alarms, keep H66 running.

You should not have both an RMU-40 room controller installed for circuit 1 in parallel with the enabled H66 emulation. They will both send updates and conflict.

This RMU-40 emulation is only for heat circuit 1 (ONE), not 2 or 3, etc. However you can have an RMU-40 in use for circuit 2 or 3 the same time as H66 is enabled for circuit 1.

How to set it up.

To enable, set “ROOM CTRL” setting to 1 in H66 config.  Restart H66.

Of you already have installed a BT50 cable based indoor sensor it has to be disconnected. Plint X6 (3-4)

At the pump display, enter Service menu and select 5.2 System settings.
Select  5.24 accessories / tillbehör. Select room system 1 and check its box.

Now you are done and the temp 20.00c should be seen in the display after max 30 seconds. You can test to change the 02F1 setting from the H66 web interface to verify that display changes on pump. 

If you want to revert this and go back to not using room sensor you just go into the same service menu and uncheck the room system 1 and set ROOM_CTRL=0 in H66.

Lastly you can now start building you automation from Home Assistant or other solution.
Note that if you use Rest API you must supply the temperature times 10. So if you want to set 22 degrees, send 220. This is not applying to MQTT.

How can we help?