When installing a low water cut-off on a hot water heating boiler, you may install it ____________________ .

When installing a low water cut-off on a hot water heating boiler, it is crucial to position the device in a location that ensures it functions effectively in monitoring water levels. The correct placement is above the lowest safe permissible water level, which allows the cut-off to activate before the water level drops to a point that could damage the boiler system. Additionally, installing the cut-off before the first stop valve ensures that it can accurately read the water level in the system and respond appropriately without being interrupted by shut-offs in the water flow.

This configuration prevents situations where the boiler could run low on water without the cut-off intervening, thus safeguarding both the equipment and the system's integrity. Positioning it incorrectly—like at the bottom of the boiler, at the highest point, or near the pressure relief valve—would compromise its effectiveness, either by ensuring it does not detect low water levels properly or by creating operational inefficiencies.