A guide to maintaining high-efficiency boilers

Generally, a boiler heats water that’s delivered through copper and/or plastic (PEX) pipes inside a building’s walls and floors. Popular high-efficiency boilers tend to be more expensive at installation, but lower utility bills pay you back after time. In fact, the U.S. Department of Energy estimates that replacing an older boiler system with a new, high-efficiency one can cut fuel bills in half. To protect that investment, high-efficiency boilers need some maintenance, just like your car. 

Why high-efficiency boiler maintenance is important

High-efficiency boilers especially benefit from the right maintenance because of the technology inside—some achieving upwards of 95 percent efficiency. The intense environment inside a high-efficiency boiler should be monitored and serviced to maintain its peak efficiency and keep things comfortable:  

• The combustion and extreme temperatures created in the heat exchanger in order to heat the water can lead to residue.
• Rapid temperature changes form condensation and combustion byproducts that can lead to drainage clogging.
• A byproduct of the combustion process can mix with condensate and raise pH to damaging levels.  
• The repeated firing of the boiler flame wears on the flame rod sensors the boiler depends on. 
• Air intake pipes can accumulate debris and can stall the system.
• The air intake pipe or vent could be clogged causing your system to occasionally stall out or lock out which will leave you without heat or hot water.
• Water levels must be maintained properly to prevent permanent damage.

Routine boiler inspection checklist 

Whether you’re a homeowner or a building professional, there are routing steps you can take to keep your high-efficiency boiler performing. Some of these you can do in passing, others are more involved and can be done less frequently. If you notice any issues, we highly recommend you contact the contractor who sold you the unit for a solution. Here are some of the inspection and maintenance steps you can take at your home or facility:  

• Check the air vents and flues for any blockage and clear, if able
• Look at the pressure gauge to ensure the water level is staying about the same—system pressure declines as water is lost
• Keep an eye out for dripping water, it may indicate pressure issues
• Clear the area around the boiler. All those boxes, bags and other stored items should be moved away to allow the boiler to breathe as well as any chemical containers such as solvents and cleaners
• Check piping for any signs of leakage or deterioration 
• Investigate the condensate drain line, PVC fittings, drain system, and drain trap for blockages

Book an annual boiler service appointment

Boilers should be inspected and serviced by a professional installer or technician at least once a year. Even if you’ve taken good care of your high-efficiency boiler, the trained eye of a professional can address smaller issues and prevent bigger more expensive repairs or replacement—again, to protect your investment. Each contractor is a little different, but during a tune-up or maintenance visit, technicians will typically:

• Clean and inspect the heat exchanger for wear and tear
• Check and clean burner assembly
• Test low-water cutoff  
• Ensure all electrical wiring is intact and joint/pipe connections are secure
• Test water pH levels to make sure they are in a safe range
• Clean, flush and inspect condensate systems
• Make sure the system fires up properly, by testing and clean sensors, ignitor, and burner assembly
• Check the venting system for deterioration, corrosion, or blockage
• Check settings and test safety and operating controls
• If system water is dirty, power flush the system piping to maintain efficient water flow
• Check for correct boiler operation once the boiler has been cleaned and examined