HVAC/R Specialists Serving Reading & Berks County

Boilers, Furnaces, and Heat Pumps, Oh My!

With all this talk of getting your heating system serviced before winter, you might be asking yourself whether you have a boiler, a furnace, or a heat pump system. So, let me explain the different types of heating systems that are typically found in the average home.


The primary function of furnaces is to raise the temperature of the air inside a home through the ducts and ventilation system.

The most common type of heating system in the United States is a Natural Gas or Propane fired furnace. Furnaces are hooked up to either the natural gas line from your utility company or to a propane tank located outside your home, similar to that used by a gas stove, gas dryer, or gas fireplace. The gas, whether propane or natural gas, ignites inside the heat exchanger, and the heat from there is transferred to the flowing air from the furnace blower through the ducts to heat the property. Propane furnaces, another type of gas furnace, are only used about 10 percent of the time as some properties do not have a natural gas hook-up and require regular fill-ups of the propane in the tank located outside of the residence.

Heat Pump systems are used when natural gas or propane is not an option and transfer heat in the duct and ventilation system. The heat pump is located outside similar to an air conditioning unit. The heat pump unit will transfer heat from outside and bring it inside to the air stream. On days that are below 35 degrees, the auxiliary resistance heat will then assist the heat pump.

Oil furnaces are more common in the northeastern US to combat the bitter and brutally cold winters as an alternative when Propane or natural gas is not available, but keep in mind that oil furnaces are second to that of natural gas furnaces in terms of efficiency.


Boilers, on the other hand, have an entirely different design and function than furnaces. While they do have a combustion chamber, a boiler’s main function is to rapidly heat water for commercial or residential settings and conduct heat to pass through pipes and radiators. Unlike furnaces and heat pump systems, boilers can only process heat, meaning any cooling or air-conditioning needs will have to be handled with an entirely separate unit.

Gas boilers operate when the thermostat calls for heat and will switch the boiler on and ignite the gas inside the combustion chamber, thus heating the water in the heat exchanger and then circulating the water that is inside the boiler. From there, the water is sent through the pipes to the radiator, where the thermal energy will be transferred into the air, thus returning to the boiler significantly cooler than when it left. Oil boilers are very similar to gas boilers, aside from the fact that their source is an oil tank that stores the fuel that the boiler needs to fire.

Watertube boilers get their name from the multiple pipes found inside the boiler that when heated produce large quantities of 190-degree water which is then to be circulated through the pipes and radiators.

Electric boilers get their name from the same concept as, gas, and oil boilers, but with a different source of energy. The electric boiler energy source is electricity. Most electric boilers will be hooked up to the same energy source as the rest of the property. But then operate in the same fashion as the oil, propane, or natural gas boilers.