What Is a Heat Pump Water Heater?

If your electric water heater is getting old, you have probably seen heat pump models on the shelf next to standard tanks. They cost more up front, look taller, and promise much lower bills. This guide explains what a heat pump water heater is, how it works, where it fits and what it can save. If you want help deciding, see our heat pump water heater installation service in Newark.

What is a heat pump water heater, in plain words?

A heat pump water heater is a storage tank with a small heat pump built into the top. The heat pump works like a refrigerator in reverse. Instead of pulling heat out of a box and dumping it into the room, it pulls heat out of the room air and puts it into the water.

Because moving heat takes much less electricity than creating it, the unit uses far less power than a standard electric tank. ENERGY STAR says labeled models use about one-quarter of the energy of a standard model.

Most units are called hybrids because they also have electric heating elements, like a regular tank. The elements kick in when you use a lot of hot water at once, or when the air around the unit is too cold for the heat pump.

How does a heat pump water heater work?

The process runs in a loop:

1. A fan pulls in room air across a cold coil called the evaporator.
2. Refrigerant in the coil absorbs heat from the air, even if the air is only mildly warm.
3. The compressor squeezes the refrigerant, which raises its temperature.
4. Hot refrigerant passes heat into the tank water through a condenser coil.
5. Cooled, drier air blows out of the unit, and the refrigerant cycles back.

ENERGY STAR's heat pump water heater guide says these units can deliver hot water up to five times more efficiently than standard electric resistance, gas and propane water heaters. They also burn no fuel, so they make no carbon monoxide.

Heat pump vs. standard electric vs. gas: a quick comparison

What are the space and power needs?

This is where many homes run into trouble, so check these before you buy.

• Air volume. ENERGY STAR says most models need about 700 cubic feet of air space, roughly a 10 by 10 foot room with a 7-foot ceiling. Some run with 450 cubic feet. A closet usually needs a full louvered door or ducting.
• Temperature. Units work best where the air does not regularly fall below about 38°F. Basements and attached garages often work.
• Height. Tanks are taller than standard models, often 60 inches or more. Measure ceiling height and the path in.
• Power. Most models need a 240-volt circuit, often 30 amps. Some newer units run on 120 volts.
• Drain. The unit makes clean, non-acidic condensate that must run to a drain or a small pump.
• Filter access. You need room to reach and clean the air filter.

What do the operating modes mean?

Most units offer several modes:

The U.S. Department of Energy's Federal Energy Management Program notes that hybrid mode, with an energy factor of 2.0 or higher, should meet hot water demand while using far less energy than standard electric models. Electric-only mode runs around 0.90 and should be used sparingly.

How much can a heat pump water heater save?

ENERGY STAR estimates an ENERGY STAR heat pump water heater could save a household of four about $550 a year on electric bills and more than $5,600 over the unit's life, compared with a standard electric model. Savings are smaller for households that use less hot water or that are switching from gas.

The U.S. Department of Energy's 2024 water heater standards will push most common-size electric tanks toward heat pump efficiency starting in 2029. DOE estimated that replacing a standard electric tank with a heat pump model meeting the new rule would save about $1,800 over the life of the appliance.

Delaware rebates for heat pump water heaters

Energize Delaware lists a $1,100 rebate for heat pump water heaters ($1,350 for assisted homes) through its Home Performance with ENERGY STAR program. Delaware Electric Cooperative members may also qualify for a separate utility rebate. Programs change, so check the details in our guide to heat pump water heater rebates in Delaware before you buy.

In Delaware, the plumbing side of the install falls under a state plumbing license, and a new 240-volt circuit is electrical work with its own permit.

Is a heat pump water heater right for you?

It is often a great fit if:

• Your current heater is electric and near the end of its life
• The heater sits in a basement, garage or large utility room
• You want lower bills and do not mind a slightly higher price up front
• Your basement gets damp in summer

It may not fit if the only spot is a small sealed closet, the space gets very cold, or you need a large amount of hot water very fast. In that case, a high-recovery gas tank or a tankless water heater may suit you better.

How to keep a heat pump water heater running well

• Clean the air filter every 6 to 12 months, as ENERGY STAR advises.
• Clear the condensate line once a year.
• Flush the tank yearly to remove sediment, like any tank.
• Check the anode rod every few years; see our anode rod guide.
• Do not wrap it in an insulation blanket. FEMP notes that a blanket can block airflow and may void the warranty.

Local note: Unfinished basements in Hockessin and suburban Wilmington often have the air volume these units need. In Middletown, all-electric homes on municipal power should ask the town about local programs, and many Bear townhomes need a louvered door or a garage spot.

Related reading: Compare options in tankless vs. tank water heaters and budget the project with our water heater replacement cost guide for Delaware.

When should you call a water heater professional?

Call a pro before you buy if:

• You are not sure the room has enough air or height
• You need a new 240-volt circuit or panel space
• There is no floor drain nearby for condensate
• You are switching from gas and need the gas line capped safely
• You want help with rebate paperwork and model selection

Thinking about a heat pump water heater in Newark? Call (302) 732-0874 for a heat pump water heater installation quote from Newark Heater Pros.