Which is an appropriate installation location for a service switch?

The most suitable installation location for a service switch is within arm's reach to observe the flame. It is critical for a service switch to be located where the operator can easily and safely access it in case of an emergency. The ability to observe the flame while being able to quickly operate the switch ensures that the technician is equipped to respond effectively if any unsafe condition arises.

Accessibility is essential because in situations involving fire or equipment malfunction, quick action can prevent further hazards or damage. This setup allows for both visual monitoring of the flame, ensuring safe operation of the equipment, and immediate control over the power supply if necessary.

The other options, while they consider safety in some aspects, fail to provide the same balance of accessibility and observation that is critical in managing fuel-related installations effectively. Safe operation practices prioritize both the ability to act swiftly and the continuous monitoring of potential hazards.