Total U.S.a

Single-family 

detached

Single-family 

attached

Apartments 

(2–4 unit 

building)

Apartments

(5 or more 

unit 

building)

Mobile 

home

All homes 123.53 77.07 7.45 9.34 22.84 6.83

Fuel used by main water heater

Natural gas 59.33 40.37 4.18 4.72 8.79 1.28

Electricity 57.04 31.21 3.09 4.26 13.32 5.17

Propane 4.12 3.37 0.09 0.10 0.20 0.36

Fuel oil or kerosene 2.62 1.88 0.06 0.22 0.45 Q

Some other fuel 0.41 0.25 0.02 Q 0.08 Q

Size of main water heater

Small (30 gallons or less) 13.28 4.96 0.77 1.75 4.09 1.70

Medium (31 to 49 gallons) 55.37 34.83 3.94 4.73 8.20 3.67

Large (50 gallons or more) 46.85 31.44 2.35 2.61 9.17 1.28

Tankless 8.03 5.84 0.39 0.25 1.37 0.18

Age of main water heater

Less than 2 years old 17.65 12.64 0.84 1.01 1.74 1.42

2 to 4 years old 22.49 15.10 1.61 1.75 2.87 1.16

5 to 9 years old 38.96 22.91 2.56 4.04 7.65 1.80

10 to 14 years old 25.10 14.94 1.35 1.70 5.82 1.28

15 to 19 years old 10.35 6.36 0.57 0.48 2.27 0.67

20 years or more 8.98 5.12 0.52 0.36 2.47 0.50

Fuel used by secondary water heater

Natural gas 2.34 1.79 0.12 0.10 0.29 Q

Electricity 2.92 2.28 0.10 0.10 0.41 Q

Some other fuel 0.48 0.42 Q Q Q N

Does not have a secondary water 

heater 117.78 72.58 7.22 9.13 22.10 6.75

Data source: U.S. Energy Information Administration, Office of Energy Demand and Integrated Statistics, Form EIA-457A of the 2020 

Residential Energy Consumption Survey

Notes: Because of rounding, data may not sum to totals. See RECS Terminology for the definitions of terms used in these tables.

a Total U.S. includes all primary occupied housing units in the 50 states and the District of Columbia. Vacant housing units, seasonal units, 

second homes, military houses, and group quarters are excluded.

Q = Data withheld because either the relative standard error (RSE) was greater than 50% or fewer than 10 households were in the 

reporting sample.

N = No households in reporting sample. 

Preliminary data release date: May 2022 

Final data release date: March 2023

Table HC8.1 Water heating in U.S. homes, by housing unit type, 2020

Number of housing units (million)

Housing unit type
Total U.S.a

Single-family 

detached

Single-family 

attached

Apartments 

(2–4 unit 

building)

Apartments

(5 or more 

unit 

building)

Mobile 

home

All homes 0.00 0.00 0.00 0.00 0.00 0.00

Fuel used by main water heater

Natural gas 0.75 0.77 2.82 3.37 2.28 7.06

Electricity 0.80 1.05 3.87 3.81 1.51 1.86

Propane 4.44 4.75 21.90 25.65 20.46 16.18

Fuel oil or kerosene 5.20 5.30 25.41 25.13 18.92 77.89

Some other fuel 16.08 13.04 41.71 55.79 35.66 100.93

Size of main water heater

Small (30 gallons or less) 2.50 5.02 9.24 6.58 4.65 6.38

Medium (31 to 49 gallons) 1.02 1.29 2.42 3.51 2.57 3.00

Large (50 gallons or more) 1.04 1.19 3.56 5.56 2.86 7.71

Tankless 3.52 3.96 12.24 23.54 9.07 22.73

Age of main water heater

Less than 2 years old 2.02 2.46 8.40 10.64 7.21 7.77

2 to 4 years old 1.87 2.26 7.03 7.66 6.79 8.60

5 to 9 years old 1.12 1.57 4.79 4.70 2.76 6.42

10 to 14 years old 1.66 2.21 6.56 7.68 3.96 7.49

15 to 19 years old 2.95 3.47 10.21 17.73 6.04 11.32

20 years or more 3.03 3.38 9.92 18.13 5.94 14.00

Fuel used by secondary water heater

Natural gas 5.83 5.82 22.44 44.15 21.06 64.81

Electricity 4.87 5.27 22.93 39.94 15.03 39.47

Some other fuel 12.64 12.72 70.91 59.85 54.53 0.00

Does not have a secondary water 

heater 0.17 0.21 0.50 0.62 0.43 0.51

Preliminary data release date: May 2022 

Final data release date: March 2023

Relative standard errors (RSEs) for Table HC8.1 Water heating in U.S. homes, by housing unit type, 

2020

RSEs for number of housing units

Housing unit type

Data source: U.S. Energy Information Administration, Office of Energy Demand and Integrated Statistics, Form EIA-457A of the 2020 

Residential Energy Consumption Survey

Notes: See RECS Terminology for the definitions of terms used in these tables.

a Total U.S. includes all primary occupied housing units in the 50 states and the District of Columbia. Vacant housing units, seasonal units, 

second homes, military houses, and group quarters are excluded.