HOW TO DISCONNECT ON/OFF SWITCH AND CONNECTION TO MICRO SWITCH.
IN THIS WAY, THE DIGITAL THERMOSTAT IS ALSO DISCONNECTED.
That way, it can be tested if ON/OFF switch or digital thermostat are working correctly.
The difference then is that the pump controls start/stop and the heater can function normally but not be controlled with ON/OFF.
So, in principle ON/OFF switch is not needed when you know this.
See picture:
Disconnect 1 and 2 as the picture below shows:
Connect 1 and 2 as the pictures below show:
Now the Digital Thermostat (if such exists) and ON/OFF button disconnected.