Your Guide to Home Boiler Maintenance & Boiler Heating System

Does your home have a boiler? If so, do you know what type of boiler it is? Learn how a steam heat boiler differs from forced air boilers and how each type affects energy efficiency.

Electric boiler system

Many modern homes use different types of boilers to heat water and distribute steam, hot water, or warm air to heat the residence. If your home uses a boiler heating system, you’ll want to make sure it’s in good working condition before the coldest winter months arrive. To get you ready, we're going to touch on each type of home boiler and provide some maintenance tips to help keep your system running efficiently this winter—and throughout the year.

But first, let’s understand the differences between a furnace and a boiler. While many people refer to any system that heats their home as a furnace, the two are different. The main difference is that a furnace heats air and uses ductwork to circulate that air through your home. Generally, a boiler heats water that moves either water or steam through copper pipes to keep your home warm and comfortable via a boiler radiator; some boilers use a combination of heated water and air and both copper tubing and ductwork.

Steam and Water Heating Systems


Home boiler systems and radiators aren’t typically installed in new homes, but this type of system is still used in many older homes, apartments, multifamily dwellings, and older office buildings.

In steam heat boiler systems, a boiler heats water, usually by means of gas or fuel oil, and turns it into steam. The steam travels through pipes to radiators or convectors, which give off heat and warm the rooms in your house. As the steam cools, it condenses back into water and returns to the boiler to be heated again.

Hot water boiler systems operate on the same principle, pumping hot water through the system to heat the boiler radiators. A variation of this system distributes hot water and heat through tubing embedded in the floor or through baseboard units mounted along the walls.


Even though these steam and water systems are somewhat dated, they have several advantages:

  • They have fewer moving parts, and if properly maintained, steam and hot water boiler systems are more durable and reliable than newer, more complicated heating systems.
  • They provide clean, dust-free heat—a huge advantage if family members suffer from dust and other allergens in the air.
  • They help maintain the original appearance and ambiance of historical homes and buildings.


  • Heat distribution is often inefficient and uneven.
  • Though they have fewer moving parts, they require diligent gas boiler maintenance to last.
  • Installation of embedded tubing in floors is expensive, and access to the tubing is difficult if problems develop.
  • Baseboard units must remain unobstructed, which can create issues with furniture placement and drape design.

Forced Air Boiler System

In this variation of the boiler heating system, water is heated in the boiler and sent to a hydronic coil, similar to the refrigerant coil in an air conditioning system. When the hydronic coil heats up, a blower distributes warm air via ductwork throughout the home or building, and the water circulates back to the boiler to be reheated.


  • Air moved through the system can be filtered, humidified, or dehumidified, as desired.
  • Newer forced air systems tend to be more efficient than systems more than 10 years old.


  • Requires ductwork and takes up space in walls.
  • The ducts and the air in the ducts must first be heated before the system can heat your home or building, which means a forced air home boiler system loses a lot of the heat it generates.
  • Moving air can distribute dust and allergens.

High-Efficiency vs. Standard Boiler Replacement

Federal regulations require that new boilers display their Annual Fuel Utilization Efficiency (AFUE) rating so consumers can make comparisons. High-efficiency boiler installation tends to be more expensive because a house generally must be retrofitted to handle the boiler; but that cost tends to be offset by lower utility bills. notes that high-efficiency heating systems have an AFUE rating between 90 and 98 percent, while older models have AFUE ratings between 56 to 70 percent. So, the more efficient the system, the less heat loss your home will experience (and the more you’ll save on your heating bill).

Boiler Maintenance


Regardless of the differences between various systems, proper boiler maintenance is needed to keep your system running efficiently.

It’s a good idea to have your boiler system checked at least once a year by a licensed residential boiler repair professional. A skilled technician can make the checks and adjustments needed to ensure that your boiler operates efficiently and safely. (Check out our furnace and boiler safety tips).

Between the professional service calls, there are things you can do to help maintain your boiler system. Add these items to your winter maintenance checklist, and your boiler should be in tip-top shape for the cold weather.

  • If you have boiler radiators and some don’t heat sufficiently when the boiler is turned on, it’s a good idea to bleed them. (It’s not as strange as it sounds—trust us.) Place a protective cloth on the floor and use a radiator key to open the radiator valve. You should hear a hissing sound as air comes out of the radiator. When the hissing stops and water starts flowing out of the radiator, close the valve and mop up any leaked water. The radiator should now heat evenly. 
  • Check the air vents and flues. Blocked air vents prevent your home boiler from operating efficiently. If you find any blockage, clear it away to allow the free flow of air.
  • Check the water level in the boiler. If the water level is below the manufacturer’s suggested level, check for any plumbing leaks that need to be repaired. Operating a boiler heating system without a sufficient amount of water can damage it beyond repair.
  • Check the boiler overflow pipe for dripping water. If this occurs, it could mean the pressure release valve is defective and needs to be replaced by a skilled technician.
  • Clear the area around the boiler. All those boxes, bags, and other stored items should be moved away to allow the boiler to breathe.
  • Look for a blue flame. If the flame on your boiler is yellow or orange rather than blue, call a technician. A yellow or orange flame may indicate a faulty boiler.

Now that you’re armed with all there is know about residential boiler maintenance, you can stay warm and cozy all winter long.

However you choose to heat your home this winter, you'll want to protect the investment you've made in your heating system. To further minimize the costs associated with issues with your home's heating system, get an American Home Shield® home warranty, which includes boiler heating systems. Our flexible coverage plans can help you protect your home as well as your household budget. Read more about how a home warranty works.

AHS assumes no responsibility, and specifically disclaims all liability, for your use of any and all information contained herein.

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New Jersey Residents: The product being offered is a service contract and is separate and distinct from any product or service warranty which may be provided by the home builder or manufacturer.