What is a common safety device found on both steam and hot water boilers?

A low water cut off is a crucial safety device utilized in both steam and hot water boilers. Its primary function is to detect the water level within the boiler and automatically shut off the burner if the water level falls below a predetermined threshold. This is essential for preventing the boiler from running dry, which can lead to overheating and potentially cause damage or a catastrophic failure.

In steam boilers, the lack of water can lead to dry firing, where the burners overheat without water to absorb the heat, leading to damage. Similarly, in hot water boilers, low water levels can cause the system to overheat, resulting in pressure build-up and possible explosions. Therefore, the low water cut off is vital for operational safety, ensuring that the boiler maintains an adequate water level to function correctly and safely.

While other devices such as pressure gauges and temperature controllers are also important for monitoring operational parameters, they do not directly prevent the critical condition of low water. A blower fan is used for combustion air but does not serve the safety function related to water levels. Thus, the low water cut off stands out as an indispensable safety device in boiler systems.