FAQ & Troubleshooting

Controller in monitor/readonly mode (cannot set temperature, etc.)

Try changing the "Master Member ID", this is most likely the problem. If you don't know which identifier is valid for your boiler, you need to use brute force.
Receiving a SUCCESS response to ID 1 in the logs indicates that the master member ID is probably correct.

The boiler does not respond to setting the heating temperature.

Try on "Opentherm summer/winter mode", "Opentherm CH2 enabled", "Opentherm heating CH1 to CH2" checkboxes one by one and all together on the "setup" page. If this doesn't work, see above.
Some boilers require the target temperature on the panel to be set to at least the maximum expected to be set by OpenTherm, acting as a hard limit on the OpenTherm requests. Some boilers report the target temperature on the panel as the max heating limit in OpenTherm diagnostic.
The heating must be enabled before the controller will issue a target temperature request to the boiler.

My boiler does not have a hot water heating function. How to turn it off?

Uncheck "Opentherm DHW present" on the "setup" page.

My boiler does not stop heating the heat carrier even if I turn off the heating.

Try on "Modulation sync with heating" checkbox on the "setup" page.

My DHW does not work when the heating is turned off.

Try off "Modulation sync with heating" checkbox on the "setup" page

How can I activate deactivated sensors and settings in my Home Assistant?

You need to open the device page, at the very bottom of the Configuration/Diagnostic card you will see the inscription “+N entities not shown”, click on it, a list of deactivated entities will appear. Select the one you want to activate and click on it. In the window that appears at the top there will be a gear icon (settings), click on it. In the window that appears, turn on the "Enabled" option and save. After some time, the activated entity will appear in the list.

My boiler display does not update with the new setpoint

This is normal; when connecting OpenTherm devices, the setpoint temperature is usually not displayed and does not change on the boiler display.

How do I convert the temperature request/response data into a value in °C?

(ID_1_request & 0xFFFF) / 256d = requested target temperature in °C

How do I enable the external pump via my Home Assistant?

You can turn on an external pump by the event of turning on the binary_sensor.opentherm_heating sensor in the home assistant.