Boilers

THE PRODUCT:

Residential boilers heat water and provide either hot water or steam to heat a home. Heat is generally distributed from the hot water or steam to the home using radiators.

THE STANDARD:

The current standards for residential boilers took effect in 2021 and require gas-fired and oil-fired hot water boilers to meet minimum efficiency levels of 84% and 86%, respectively

In 2023, DOE proposed amended standards for gas-fired and oil-fired hot water boilers of 95% and 88%, respectively. If finalized, the proposed standards would effectively require all new gas-fired hot water boilers to use condensing technology. Condensing boilers extract additional heat by condensing the water vapor in the flue gases, resulting in efficiency levels of 90% or higher. 

*Annual fuel utilization efficiency (AFUE) is the energy efficiency metric for boilers and refers to the portion of energy in the fuel that is converted to useful heat. 

KEY FACTS:

As of 2020, a little over nine million US homes were heated with boilers, around 65% of which are in the Northeast. Air-to-water and water-to-water heat pumps are efficient electric alternatives for hydronic heating. Air-to-water and water-to-water electric heat pumps meet the definitional criteria to be classified as consumer boilers and are commercially available in the US.; however, at this time, there are no federal efficiency standards for these products due to the absence of a federal test procedure.