Efficient boilers and furnaces


About half of the energy we use at home goes into heating and cooling.  We need to be comfortable in our homes, and heating needs to be affordable.  At the same time, as a society we need to reduce our CO2 emissions.  How is this going to be possible?  Fortunately, technology is coming to the rescue!  Recent years have seen remarkable improvements both in conventional heating systems using oil and natural gas and also in high-efficiency heat pump heating and cooling systems.  Taking advantage of these requires informed investment in the right equipment, which can pay off within a few years in many cases.

Recommended Actions:

  1. Upgrade to a more efficient boiler or furnace, and system improvements. If a heat pump upgrade doesn’t make sense financially, and your current heating system is of relatively low efficiency, upgrading to a new furnace or boiler can make a big difference both on your heating bill and your comfort.

Financial Considerations

Cost and efficiency of heating systems

An EnergyStar rated natural gas boiler or furnace efficiency is as high as 95 to 98% (for oil, around 90%), with improved features that add up to around 25% lower fuel cost than a typical 1990’s system.

          CO2 Footprint of Heating Systems

FAQS – Upgrading your conventional system:

Q: How do I know how efficient my current system is? A:  An annual inspection measures combustion efficiency of boiler or furnace; overall efficiency can be quite a bit lower, from losses in ducts or pipes, or standing losses for a boiler.

Q: How large a system do I need, and how is that rated? A: A typical sized home heating system has a capacity of around 100 MBtu/hour, depending on the home size and how well weatherized it is.  Your existing system, if it keeps you warm enough, is sized large enough, and if you improve on your home’s insulation and/or air-sealing you will have a good margin of safety.

Q: Should we switch to natural gas which people say is cleaner than oil? A: Natural gas is cleaner than oil when combusted, but its total environmental impact is worse due to methane leakage.  It is less expensive than oil to heat with but may be expensive to connect to the home, if it is even available as an option.

Q: Should I switch to electric thermal storage (ETS) to save money, and is that clean? A: No!  ETS and baseboard electric heat are the worst environmental options currently.  However, heat-pump(s) may be an excellent option to switch to if you currently heat with propane, electric or fuel oil.


  • MassSave offers up to $2,300 rebate for upgrading to a high-efficiency Natural Gas furnace or boiler or Fuel oil furnace or boiler. The full rebate requires taking advantage of a free energy audit.  Ask your HVAC contractor for details.


  1. MassSAVE rebates
  2. Department of Energy guide to home heating systems
  3. Environmental Protection Agency, EnergyStar guide to home heating and cooling
  4. For locating an HVAC contractor, take advantage of independent reviewers such as Angie’s List (angieslist.com), Consumer’s Check-Book (www.checkbook.org) and others.