LG THERMA V Series Installation Manual page 62

Check Points, Maintenance and Troubleshooting
Disturbances in the operation
In case of a malfunction during the operation of the device the screen of the internal unit displays
"Caution, malfunction".
Search for the malfunctioning message in the manual. For error correction, call the installer who
performed the installation of the device.
Reset of the thermal protection of the electrical heater
The thermal protection of the electrical heater additionally protects the device in the following cases:
• The electrical flow heater can be permanently short-circuited.
• At commissioning, air is in the system; this causes heating without heat extraction.
The easiest way to determine whether the thermal protection of the electrical heater is turned off is
to turn on the operation of the auxiliary source on the control unit. Determine the feeling by hand the
difference between the supply line and the return line. The electrical heater works if the supply line
is warmer. Activation of the auxiliary source is explained in the manual.
In case the electrical heater does not work because of one of the aforementioned reasons, the
safety thermostat has to be reset after the problem is resolved.
Firstly you have to remove the front bottom panel.
Reset the safety thermostat by pressing the red button until you hear a "CLICK".
Resetting the device can only be performed by installers, authorized contractors for commission or
authorized maintenance worker in a voltage-free state.
Turn off the power before proceeding with maintenance.
62 Air-to-Water Heat Pump
Safety thermostat