Two main reasons, If you need to re-boot the system, or you’re in storage with power, but don’t need to run the heat or A/C.
1) If the ON/OFF switch isn’t installed, the only way to reboot the system is to either remove the 5 amp ECC fuse from the 12 volt fuse panel, or remove / re-install the 12 volt connector on the control module. We don’t like this option because of the risk of pulling wires out of the connector, shorting out the connector, installing the connector incorrectly, etc. Its just to high risk.
2) If you place your motorhome in storage yet keep shore power (i.e. keep the batteries charged) and there’s no need to run heat or A/C, then we prefer that you shut the Waiter ECC system OFF, this reduces wear and tear on the system and the touchscreen display.
The Waiter ECC kit comes with a switch, spade lug connectors, and a guarded wall mount switch plate. If you don’t want to mount the switch on a wall, another option is to simply use a couple wire ties and secure the switch to a wire bundle or somewhere that you can get to it.