Home Repair & Maintenance Ideas and Tips

Your Guide to Home Boiler Maintenance

Does your home have a boiler? If so, what type of boiler is it? Learn how steam boilers differ from forced air boilers and how 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 system, you 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 boiler system and provide some maintenance tips to help keep your system running efficiently this winter.

But first, you should know 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, though some use a combination of heated water and air, and both copper tubing and ductwork.

Steam and Water Heating Systems

Boilers and radiators are not often installed in new homes, but this type of system is still used in many older homes, as well as apartments, multi-family dwellings and older business buildings.

In steam heating 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. As the steam cools, it condenses back into water and returns to the boiler to be heated again.

Hot water heating systems operate on the same principle, pumping hot water through the system to heat the 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 a number of advantages.

  • They have fewer moving parts, and if properly maintained, steam and 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 ambience of historical homes and buildings.


  • Heat distribution is often inefficient and uneven.
  • Though they have fewer moving parts, they require diligent 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 problems with furniture placement and drape design.

Forced Air Boiler System

In this variation of the boiler 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 over 10 years old. The older systems only have an Annual Fuel Utilization Efficiency (AFUE) rating of 50-70 percent, meaning they use 50-70 percent of the fuel to heat, and 50-30 percent is wasted. In contrast, newer high efficiency boilers can have an AFUE rating of up to 90-98 percent.


- 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 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 AFUE rating so consumers can make comparisons. High-efficiency boiler installation tends to be more expensive because a house must generally be retrofitted to handle the boiler, but that cost tends to be offset by lower utility bills. The U.S. Department of Energy estimates that replacing an older boiler system with a new, high-efficiency one may cut your fuel bills in half.

Boiler Maintenance

Regardless of the differences between various residential boiler systems, proper 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 professional. A skilled technician can make the checks and adjustments needed to ensure that your boiler is operating efficiently and safely.

Between the professional service calls, there are things you can do to help maintain your boiler system.

- If you have radiators and some don’t heat sufficiently when the boiler is turned on, it’s a good idea to bleed them. 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 the 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. Operating the boiler without a sufficient amount of water can damage it beyond repair. If the water level is below the manufacturer’s suggested level, check for any plumbing leaks that need to be repaired.

- 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.

Finally, don’t try to repair the boiler yourself. Always have a licensed technician make all boiler repairs on your system.

However you choose to keep your home warm and cozy this winter, you'll want to protect the investment you've made in your heating system. To further minimize the costs associated with the repair and replacement of your home's heating system, consider purchasing an American Home Shield® Heating Home Warranty. Our flexible plans can help you protect your home as well as your household budget.

DIY tips are for informational purposes only. Learn more.