F1p
24 July 2025 11:55
368
Thanks for sharing,
# Using the onboard Compensation Curve
### About
The software has the ability to store a custom compensation curve onboard - this overcomes some limitations with the Ecodan and allows advanced features to be input.
* The Ecodan Main Room Controller (MRC) has the ability to design a curve with a maximum of 3 points, there is no limit to the number of points which can be sent to the CN105 Ecodan Bridge device.
* There is also no ability to add an +/- offset to the current curve remotely, only by adjusting on the the controller screen. By moving the curve onto the CN105 Ecodan Bridge, an offset can be adjusted remotely.
* The Ecodan uses the Outside Air Temperature (OAT) sensor located on the back of the outdoor unit, this sensor can be influenced by the likes of direct sunlight. By moving the curve onto the CN105 Ecodan Bridge it's possible to use another temperature source to determine the flow temperature.
* The Ecodan cannot automatically adjust for other influencing factors, such as heat loss due to wind or solar gain. By moving the curve onto the CN105 Ecodan Bridge it's possible to automate the offset when conditions may influence the building.
The device can continue to calculate and input to the curve if the connection is broken.
### How to Design, Modify and Operate
The Ecodan is to be placed in Fixed Flow mode, as the value is calculated by the device it will then adjust the flow temperature setpoint automatically which recreates the method the Ecodan uses.
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You need to send your curve design points as JSON to the device and activate
2 Likes
gekkekoe
24 July 2025 12:26
369
I could be mistaken, but I think @samumar82 is running my esphome impl by looking at the names..
Seems like he’s affected by this issue OTA -> Wifi setup · gekkekoe/esphome-ecodan-hp · Discussion #165 · GitHub
@samumar82 try a new factory bin and see if next OTA is forgetting your wifi credentials.
@gekkekoe you are correct. I’m ok with the wifi credentials, will try to do the “visit” trick next time. @F1p I’m not sure I got it right: should I delete my autmation, create the json and send it via mqtt and keep the pump set to fixed flow? Can I use the same also for cooling? One last question, how is the machine calculating the slope? I mean I can see fixed values based on external temp. but what in the middle?
F1p
24 July 2025 12:53
371
If you are esphome version from @gekkekoe you will not be able to use this feature. You will also have different update method.
It is available on MQTT version only
I did not implement for cooling flow yet, because I understand humidity is more important than Outside Air temperature. It is possible though
gekkekoe
24 July 2025 12:53
372
the json curve stuff is for his implementation, so you should flash his implementation to use that.
ok thanks all for claryfing
ajdunlop
1 August 2025 12:11
374
Looking forward to trying this although might need to wait a couple of months to do so properly.
1 Like