In this section
- CalculatorCost calculatorCompare the yearly cost of an electric resistance tank, a gas tank and a heat pump water heater at your state's prices.
- Guide120 V heat pump modelsPlug-in heat pump water heaters run on a standard 120 V outlet, made to replace gas tanks without new wiring. Dedicated vs shared circuit models, sizing, space and installation.
Cheapest first
- Turn the tank down to 120°F. DOE recommends 120°F for most households; many tanks ship set at 140°F. Check your dishwasher’s needs first.
- Swap the showerhead. Standard showerheads use 2.5 gallons per minute; WaterSense-labeled heads use 2.0 or less, and good 1.5 gpm heads feel fine. Less hot water, same shower length.
- Insulate exposed hot water pipes, especially the first few feet out of the tank.
- Fix drips. A dripping hot tap wastes heated water all day.
The big upgrade
A heat pump water heater pulls heat from the air around it instead of making it with a resistance element. DOE says they can be two to three times more efficient than conventional electric water heaters. They’ve been around for years as 240 V units; the newer 120 V plug-in models are built to replace a gas tank without running a new circuit. Read how the 120 V models work, or compare yearly costs.
Many utilities and some state HEAR programs pay rebates on heat pump water heaters; the federal tax credit ended after 2025.
Picks
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Rheem ProTerra 120V plug-in heat pump water heater
Replacing a gas water heater without new wiring
- Plugs into a 120 V outlet
- Dedicated-circuit and shared-circuit models
- 40 to 80 gallons (shared-circuit model)
The first 120 V plug-in heat pump water heater, made to drop in where a gas tank was.
Watch for: Sold through plumbers and home stores, not Amazon. Plumbing and venting changes need a licensed plumber.
A.O. Smith Signature 900 120V plug-in
Second 120 V option
- 120 V plug-in hybrid
- 50 gallons, leak detection
Gives you a second quote and a different warranty to compare.
Watch for: Same installation caveat.
High Sierra 1.5 gpm showerhead
Cutting hot water without a weak shower
- 1.5 gallons per minute
- WaterSense labeled
Showers are the biggest hot water user in most homes. A good low-flow head cuts that by about 40% versus a 2.5 gpm head.
Watch for: Some people prefer a wider spray; check the spray type.
Niagara Earth Massage 1.5 gpm showerhead
Cheapest low-flow swap
- 1.5 gpm
- Fixed head
A low-cost way to try low-flow.
Watch for: Basic finish.
Water heater insulation blanket
Older tanks that feel warm to the touch
- Wraps around the tank
Cuts standby heat loss on older, poorly insulated tanks.
Watch for: Don't cover the burner, flue, controls or the data plate. Check your water heater's manual first.
Foam pipe insulation
Exposed hot water pipes
- Slit tubes, sized by pipe
Keeps water hotter on the way to the tap and is easy to fit.
Watch for: Keep foam at least 6 inches from a gas water heater's flue.