CO / COL means Commercial Lock.
This function ensures that no one can change the temperature settings.
Commercial Lock can only be activated and deactivated manually on the heater and in the app on standard Gen3 panel heaters, Gen3 floor heaters, and the CO1500MAX model.
For Gen3M and Gen4, activation can only be done through the app, but deactivation can be done both via the app and manually on the heater.
Activate/Deactivate Commercial Lock (COL) manually on Generation 3 heaters:
(The CO1500MAX uses this method)
Turn off the heater using the main switch.
Turn the heater back on using the main switch.
Within 5 seconds, press and hold the gear button for about 10 seconds until you see COL.
The display will first show CHL and then switch to COL.
Release the button as soon as you see "COL".
(Do not press/hold the button too firmly, as it may be a bit sensitive.)
Commercial Lock is now activated/deactivated.