AC•THOR / AC•THOR 9s shows "Heating Finished" but the target temperature has not been reached yet?

Our "Support" section provides valuable insights, which provide you with practical tips on the operation of our devices.

In this FAQ we address the question of why your device displays 'Heating finished,' and the green checkmark on the home screen is lit permanently, even though the target temperature has not been reached yet?


NOTE: From firmware version a0020806, this symbol has been slightly adjusted for better differentiation from the 'Standby' status. The 'Heating finished' status is now represented like the icon below:

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This applies to both the AC•THOR display and the web interface.

We recommend to check the 'Load' status on the Info page on the display or the web interface!

Detailed information about the load on the AC•THOR:

Detailed information about the load on the AC•THOR 9s:

If the load status is '0' or 'none' (for AC•THOR) or '1:0 2:0 3:0' (for AC•THOR 9s), it may have the following causes:

  • The shutdown temperature of the thermostat has already been reached.
    Please consider the current temperature in the storage! If the shutdown temperature on a heating element with a bimetal thermostat is set too low, the AC•THOR cannot reach the target temperature!

  • The connection to the heating load is otherwise interrupted.
    Perhaps the safety temperature limiter (STB) has been triggered. For my-PV immersion heaters, the STB may have been triggered by vibrations during transport! In this case, it must be manually reset.

  • A three-phase heating load has been connected to the AC•THOR 9s without a neutral conductor. The device requires a star point (neutral) at the consumer!

Good to know

You can also perform a simple functional check of the AC•THOR with another purely ohmic load or resistive heat generator. Even a simple kettle is suitable for this purpose!

Issue not resolved? Please fill out the support form.

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