The Basics of How Boiler Systems Work

Not every boiler works the same way. However, all boilers have the same primary purpose: to heat up the indoor air. When properly maintained, a boiler should last for around 15 years before needing to be replaced. Knowing how it operates can help you gather the information you need when contacting our team at Davis & Green to request repairs or install a new boiler.

What Is a Boiler?

A boiler is commonly installed in residential homes to provide people with either hot water or hot air, depending on the system. Some boilers deliver both of these functions. These systems consist of a pressure tank equipped with some type of heat transfer surface.

Step-by-Step Process on How Boilers Work

Four basic steps occur when a boiler works to heat a home or provide you with hot water.

Step One: The water is heated before being sent through nearby radiator circuits and piping. Different types of boilers work with certain fuel types to complete this process. The three most prevalent fuels used in boilers are electricity, oil, and gas.

Step Two: The system emits steam or hot water through the pipes connected to your home’s radiators.

Step Three: The steam or hot water will be sent through the radiator tubes, which allow heat to be distributed throughout nearby rooms.

Step Four: After the steam or water has been cooled, it will be sent back through the pipe system. It reaches the initial heating vessel, and the process begins again. This approach ensures that the boiler can continuously heat a building.

Primary Boiler Components

Boilers consist of a generation unit with a fuel supply, feedwater system, exhaust gas venting system, and combustion air system. Some additional components that allow a boiler to function properly include:

  • Controls and instrumentation
  • Burner
  • Deaerator
  • Fan
  • Economizer
  • Stoker
  • Tubes
  • Heat exchanger

Each Type of Boiler Works Differently

Many factors determine how boilers work, such as whether it provides heating for the home or heat and hot water. Other factors include its:

  • Fuel type
  • Pressure and temperature
  • Heating method
  • Capacity
  • Draft method
  • Efficiency

How Each Fuel Type Works

Different boilers use different sources of fuel during this process. There are differences in how the boiler works depending on the fuel source. The three primary fuel sources for boilers include electricity, gas, and oil.

Electric Boilers

Electric boilers are regularly installed in homes that don’t have easy access to natural gas. Additionally, some people prefer electric appliances over gas. In order to heat your home or the water that runs through it, the boiler will heat elements with electrical power instead of fuel.

These elements will then transfer the heat to the water. Electric boilers are great for the environment but aren’t that efficient. Maintenance can also be relatively inexpensive.

Gas and Oil Boilers

When a gas boiler receives a signal from the thermostat that heat must be provided to the interiors of a home, the boiler will use an electric start or pilot light to ignite oxygen and gas within a combustion chamber. This chamber is a secure and safe area where gas can be burned to produce a certain amount of heat.

Once the gas burns, it will heat up the nearby heat exchanger, a thick web of piping that transfers the heat to water. These boilers are commonly found in residential homes because of their low installation and maintenance costs.

The combustion process in an oil boiler is the same as that in a gas boiler. The oil will burn within a combustion chamber to heat up a heat exchanger. This process allows the water to be heated.

The primary difference between these two systems is that an oil burner must be equipped with a special oil storage tank. In most cases, homeowners with oil boilers will order oil to be delivered to their home, after which it will remain stored in a tank until it’s required. While these boilers aren’t environmentally friendly, they can be highly efficient. Maintenance costs for these boilers can be somewhat high.

Different Forms of Heating

All three types of boilers are able to heat your home with hot water or steam. However, a hot water boiler doesn’t boil the water. The water reaches a temperature that ranges from 140-180 degrees Fahrenheit. The boiler is equipped with an electrical pump to make sure that the hot water can be sent throughout your home.

Steam boilers are designed to heat water beyond the boiling point, which results in the water being converted into steam. This steam will then be distributed through your home with radiant floor systems or radiators.

More energy is required to boil water when compared to heating it, which is why steam boilers aren’t the most efficient systems around. This issue is somewhat mitigated because steam boilers don’t need the extra energy uptake that comes with a circulating pump.

Heat Only vs. Combination Systems

Boilers can also work differently depending on the system’s heating type. Standard boilers are meant to provide homes with central heating, which means the system won’t heat your water. However, other boilers function as a central heating system and hot water heater.

The boilers that deliver both of these functions can be either indirect systems or tankless coil systems. A tankless coil system uses the heat exchanger to raise the water’s temperature whenever hot water is requested from a faucet. When the faucet is turned on, water is sent over the heat exchanger before being delivered.

This form of water heating is highly efficient during the cold winter months since it benefits from the heat the unit creates to warm up your home. However, it can use too much energy during warmer summer months because at this time of the year, the boiler no longer needs to be turned on to heat your home.

While indirect systems are also designed to use the unit’s heat exchanger when creating hot water, the water will be stored within a tank. Once the hot water is sent to this tank, it will maintain its temperature until it’s requested, which means that the boiler won’t need to be turned off and on whenever you need hot water. These systems are known for their efficiency.

If you want to have a new boiler installed in your home or would like to have your existing boiler repaired, our technicians at Davis & Green will provide you with efficient service you can rely on. Our heating and cooling services apply to all systems and include repair, maintenance, and installation work. We also provide full-service plumbing, including water heater installation, drain repair, drain cleaning, leak detection and repair, sewer repair, and gas line maintenance. Consider requesting our electrical services as well if you need to have your home rewired or your electrical panel replaced. Call us today to schedule one of our services for your Richmond, VA home!

Davis & Green

company icon