A boiler is a type of central heating system. Heat is generated as the boiler does its job—boiling water in a tank, which is then dispersed throughout a building. Boilers heat and then pump water or steam through pipes in a home, and as the steam or hot water passes through the baseboards, radiators or radiant floors in the rooms of a house, the heat is released, raising the temperature in the various rooms. The water circulates throughout the pipes and is continuously heated in the boiler.
Licensed contractors, HVAC specialists or plumbers can replace outdated, oversized or broken boilers with newer, more energy-efficient models. Replacing a clunky old boiler helps save on utility bills and also reduces pollution. According to Energy.gov, older model boilers have efficiency ratings of 56 percent to 70 percent, while newer models rate as high as 98.5 percent. In addition, the Department of Energy says that upgrading from 56 percent to 90 percent efficiency in an average cold-climate house saves 1.5 tons of carbon dioxide emissions each year when talking about homes heated with gas and 2.5 tons when talking about homes that use oil heat.
The most common type of boiler that Lassaad Sanane of HVAC and Appliance Express in Sterling, Virginia, installs are natural gas boilers, although the company also boilers fueled by propane, wood, electricity and oil.
Brand and size
The size and brand of boiler both affect the total project cost, says Sanane of HVAC and Appliance Express. A key factor in selecting a new boiler is determining the BTUs required for heating a particular home. A BTU is the approximate energy needed to heat one pound of water by 1 degree Fahrenheit, according to Calculator.net. This slick BTU calculator helps estimate the amount of BTUs needed to heat a home based on its dimensions, insulation conditions and desired temperature changes. A boiler replacement specialist can also advise on the proper size and make for a particular situation.
Boiler cost and installation
The cost of replacing a boiler is most affected by the boiler itself and the cost of labor. Sanane of HVAC and Appliance Express says the average cost to replace a boiler, including labor and materials, is between $3,500 and $6,000 for a typical residential property. Prices can vary, depending on regional labor costs and the business model of the HVAC company. Sanane recommends that homeowners always have the automatic feed valve and expansion tank replaced when changing out a boiler. Many contractors will also haul off and dispose of the old boiler as well, which is helpful since they are quite heavy. Here are two examples of boiler installation costs from Sanane of HVAC and Appliance Express:
Crown gas boiler: 87,000 BTU
- Total cost to customer: $3,500
- Labor: $1,500
- Materials: $2,000, including boiler ($1,800), expansion tank ($100) and automatic feed valve ($100)
- Project time: 1 day
Crown gas boiler: 115,000 BTU
- Total cost to customer: $4,900
- Labor: $1,500
- Materials: $3,300, including boiler ($3,100), expansion tank ($100) and copper fitting ($100)
- Project time: 2 days
Purchasing the proper boiler
A properly installed boiler keeps a home warm for many years. Installing or replacing a boiler is an investment upfront, but spending the money on an energy-efficient model as well as on sealing up air leaks in a house is a sound investment that will pay for itself over time. Make sure that the boiler is the right size BTU before purchasing or installing it, says Sanane at HVAC and Appliance Express. Also, reputable brands will provide long-term product protection through their warranties. It’s also important to have boilers serviced regularly to keep them in peak operating condition.