The errors E1, E2 and E4 indicate an issue during the calibration of the Smart Radiator Thermostat. When a Smart Radiator Thermostat is attached to a mounting bracket, the device attempts to determine the positions in which the radiator valve is fully open and fully closed. This process is referred to as calibration.

If calibration fails, the Smart Radiator Thermostat will indicate the issue by showing one of the following errors.

E1 error

On the Smart Radiator Thermostat Basic, the E1 error is indicated by the warning and spanner symbols, and two dashes turning on.

An E1 error indicates that the closed position of the valve has not been detected. To resolve this, please unmount the Smart Radiator Thermostat and make sure that the mounting bracket is properly tightened to the valve body. Restart and remount the Smart Radiator Thermostat to restart calibration.

Note: If you are using an adapter, please remember that some of them may need a specific pin extender (provided in the tado° package) to work. For more information, please read this article on adapters that work with the Smart Radiator Thermostat.   

E2 error

On the Smart Radiator Thermostat Basic, the E2 error is indicated by the warning and spanner symbols, and four dashes turning on.

An E2 error is shown when no contact is detected between the motor and the valve pin. To resolve this, please make sure that the mounting bracket and the adapter (if used) are attached properly to the radiator. Restart and remount the Smart Radiator Thermostat to restart calibration.

Note: If you are using an adapter, please remember that some of them may need a specific pin extender (provided in the tado° package) to work. For more information, please read this article on adapters that work with the Smart Radiator Thermostat.

E4 error

On the Smart Radiator Thermostat Basic, E4 error is indicated by the warning and spanner symbols, and six dashes turning on.

An E4 error is shown when the distance detected between the open and closed positions of the valve is too short. This can be an indicator that the radiator valve is blocked by calcification.

Use a spanner or a similar tool to move the pin in and out to unblock the valve. Otherwise, re-install the old valve head and open/close it multiple times to improve the pin’s movement. Then, restart and remount the Smart Radiator Thermostat to restart calibration.

If this doesn’t solve the issue, it is possible that the charge of the batteries in the device is low. Please replace the batteries. Then, restart and remount the Smart Radiator Thermostat to restart calibration.

If the calibration is not successful even after several attempts, please contact us via chat with a clear picture (pdf or jpg) of the thermostatic valve body.

More information:

My Smart Radiator Thermostat shows an E0 error/the warning symbol is on. How can I fix this?

Did this answer your question?