@TNO_Marc also why do you want to reset E1 and E2? Are you using these values outside of reprap firmware? They are predominantly there dort the firmware to keep track of extrusion.

@zzing Have a read of:
https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_fans

You have set Fan 0 and Fan 1 up as thermostatically controlled fan for Heater 1 and heater 2 (so far so good). This means they will cool those extruder heatsinks from 75C and higher in your config.

You have then setup tool 0 and tool 1 to use fan 0 and fan 1 as the part cooling fans, really they should (presumably) both use fan 2?