The 30-gallon water heater is the small-household residential pick — 1–2 person households, ADUs, in-law suites, vacation cabins, manufactured homes, and small condos. Save $80–$150 upfront vs 40-gallon with adequate capacity for single-occupant or low-frequency use.
Top 30-gallon picks
Gas 30-gallon
Electric 30-gallon
30G applications
- 1–2 person household whole-house with single bathroom
- ADUs and in-law suites serving 1–2 occupants
- Vacation cabins / second homes with intermittent use
- Manufactured / mobile homes — HUD-certified 30G variants
- Garage apartments and pool houses with full-bathroom occupancy
- Lowboy installs — basement rim-joist, attic, crawlspace
30G vs alternatives
- 30G vs 20G point-of-use: 30G is whole-house; 20G is single-fixture with full bathroom. For ADU or small whole-house, 30G is more appropriate.
- 30G vs 40G: save $80–$150 with 30G; 40G is the right step-up if simultaneous shower demand is a possibility.
- 30G vs 10G mini-tank: 10G is single-fixture (under-sink); 30G handles whole-bathroom use.
Bottom line on 30-gallon water heaters
The 30-gallon water heater is the small-household residential pick. The Bradford White Compact 30G is the volume gas pick for tight-clearance closets; the AO Smith Conservationist 30G or Rheem Performance 30G Electric for all-electric installs. For larger occupancy, step up to 40-gallon. For single-fixture-only applications, drop to point-of-use mini-tanks.