Most homes today are heated during cold winter months using furnaces or boilers. These heaters work by heating the air within the device and then distribute it throughout the home by way of air ducts that are strategically placed behind the walls, under the floors, or above the ceiling or any combination of the three.

When boilers are used to heat homes, they do so by heating water that is then sent through radiant floor systems or baseboard or other radiators. This hot water can also be used to heat air inside coils. Steam boilers can also be used, but they are less efficient. For greater energy efficiency, older systems that are still in otherwise sound shape can be retrofitted to improve efficiency and safety of the appliance.

Before deciding to have old oil boilers retrofit, it is important to carefully weigh whether or not the overall condition and expected life of the entire system justifies the cost. It may be more cost effective to install a replacement unit instead. Many people today are replacing older heating units with new, higher efficiency models to which air conditioning can be added.

When choosing the retrofit option, it is important to remember that these are fuel-specific. So, if the unit is gas-fired, it will still be fueled by propane or natural gas once it has been upgraded with new ductwork, programmable thermostats, or other convenience features. The same is true for oil-fired boilers and furnaces. They will continue to be fueled by the same oil they previously ran on.

The oil boilers and furnaces of the past achieved energy efficiencies that ranged from 56% to 70%, but today's higher efficiency systems are designed to convert as much as 98.5% of the fuel used into useful heating for the home. That means installing a new system can help cut energy bills in half and reduce the pollution from an old unit by that same amount.

In addition to that, the simplest solution for most homes is to replace old, worn out oil boilers that are too large or too small for the space it has been heating for years, with modern high-efficiency models. Prime candidates for replacement are old coal burners that sometime in the past were switched over to gas or oil. Even owners of gas furnaces that eat up a large amount of energy with constantly running pilot lights have been known to benefit from the energy savings afforded by switching these units to electronic ignition.

One of the best things homeowners can do prior to buying new oil boilers or other furnace types is improve the energy efficiency of their home in other ways first. That may involve installing new windows or covering older ones with storm windows, sealing cracks to prevent air transfer, and a number of other measures. Once this has been completed, the services of a heating contractor can be enlisted to evaluate the home and recommend the correct furnace size.

A good choice when shopping for new oil boilers and furnaces is to check for the ENERGY STAR label. This will ensure that the heating system is high-efficiency and will save money over the life of the unit.