Which gauge indicates the amount of pressure in a hot water boiler?

The pressure gauge is specifically designed to measure the amount of pressure within a hot water boiler. This instrument provides critical information regarding the system's operating pressure, which is essential for safe and efficient boiler operation. Maintaining the right pressure is vital to ensure that the boiler functions correctly and to prevent potential hazards, such as overpressure situations that could lead to system failures or even explosions.

In contrast, a water gauge generally indicates the level of water within the boiler, which is important for identifying if there is sufficient water to avoid overheating or damaging the boiler. A temperature gauge measures the temperature of the water or steam in the boiler but does not provide any information about the pressure. Lastly, a flow gauge would indicate the flow rate of water or steam through the system, which is not directly related to measuring pressure. Each of these gauges plays an important role in boiler operation, but the pressure gauge is the only device used to monitor pressure levels specifically.