Boilers
Whether gas or oil, ENERGY STAR qualified boilers use about 6% less energy
than a standard boiler.

They achieve greater efficiency with improved features, including:
electric ignition, which eliminates the need to have the pilot light burning
all the time
new combustion technologies that extract more heat from the
same amount of fuel
sealed combustion that uses outside air to fuel the burner,
reducing draft and improving safety
You should know
Though these products can be more expensive to purchase up front, the
cost difference will be paid back over time through lower energy bills.
When buying new equipment, sizing and installation are as important
as product quality.
You can get better heating and cooling performance at home
with ENERGY STAR home sealing (insulation and air sealing) and duct sealing.
Consider regular maintenance to maintain your heating and cooling
system performance.