The Principles of Operating a Gas Boiler

Burner and Thermostat

• Operating a boiler begins with the thermostat. The boiler prepares water by heating it up and then allowing it to flow out whenever you use a hot-water tap. The heating process is controlled by the thermostat, which indicates a specific range that the water inside the boiler tank needs to reach. To heat incoming water, the boiler activates its gas burner, which is essentially a line or circle of holes for the gas to escape from.

Ignition

• The ignition system ensures the gas is lit as it rises from the burner. This system is also automated. When you set the boiler temperature, or when the boiler needs to refill, the signals it sends to the gas valve and ignitor are immediate. Older ignitors used constantly lit pilot lights, but modern versions have electrical ignitors that create sparks. Once the gas is lit, the heat moves through a heat exchanger into the water trapped inside the boiler tank.

Boiler Tank

• The boiler tank is the largest part of the system, and houses the water heated by the gas burner. Boiler tanks are also a common focus of long-term problems, like the growth of heat-loving bacteria and the buildup of scale from hard water. Rods and linings inside the tank help prevent these issues. Sensors placed at different levels outside the tank help monitor the temperature both at the top and bottom, so that an equilibrium can be safely reached.

Safety

• Operating a gas boiler always involves a certain amount of danger. The burners may not combust properly, allowing gas to fill the combustion chamber, creating the possibility of a fire. The boiler might overheat, creating too much steam and pressure. Temperature sensors at the burner and tank shut down the system if heat rises too quickly or too far. Boilers also come with relief valves that dislodge air and water from the top of the tank if the pressure rises too high.