How do Boilers Work?

Boiler systems are used for a variety of purposes. They were originally used to power machines and engines like railroad locomotives. Today, boilers can be used to heat your home as well as provide hot water for your faucets.

How Boilers Work

A boiler is a unit that heats a liquid in a storage tank or network of pipes to a high temperature. This liquid is circulated throughout the house by a pump to provide heat. A portion of this energy can be redirected for use in a hot water heater. The energy source used to heat the liquid can be electricity, oil or natural gas. The two main types of boiler systems are fire tube and water tube.

Fire Tube Boiler

In a fire tube system, hot gases from the burner snake their way through a network of tubes contained inside of a large storage tank. The heat from the gas is transferred to the water or other liquid contained inside the tank. The hot liquid is then circulated throughout the home’s radiant heat system. The hot gases are vented outside.

Water Tube Boiler

In this system, a narrow tube filled with water passes through the furnace where the liquid is heated directly. A water tube system produces a lower volume of hot liquid due to its design, but generates a higher level of heat. The liquid heats the house the same way as with the fire tube system.

Controlling the System

Each system will be controlled by a thermostat. When the inside temperature drops below the set point, the boiler will begin to heat the liquid. A pump will circulate the liquid throughout the system. In older homes, the hot water or steam is sent to wall mounted radiators. Newer homes may have radiant floor heat, where the hot liquid lines are installed in the floor. When the desired comfort level is reached, the thermostat turns the system off.

Troubleshooting a Fairfax County, VA Boiler System

While boilers are very reliable, any system is subject to malfunctions that will need repair. A banging sound in an older system could indicate that air is trapped inside the pipes or that they are clogged with some kind of deposit. Another common issue is that the pilot light may need to be relit on a gas or oil burner. The gas line may be clogged or the pilot light may be defective if the pilot light fails to stay on. Because electronic starters, pumps and blower fans require electricity, check for a tripped circuit breaker if your unit fails to come on. Faulty circuit breakers need to be replaced ASAP. Older units may lose pressure or leak. You should also have your thermostat calibrated. If you need assistance, contact one of our experienced boiler technicians at Brennan’s Heating & Air Conditioning.