effluent vs sump pump

Heat Pump Water Heater Rebate Program for Maine Homes

Heat Pump Water Heaters

Tens of thousands of Mainers own heat pump water heaters. They’re popular because they produce lots of hot water, help dehumidify, and can save more than $500 per year in electricity.

Heat pump water heaters work like air conditioners, but rather than moving heat from the room to the outdoors, they move heat from the room into the water tank.

Heat pump water heaters are sometimes called “hybrids” because in addition to a heat pump, they have traditional electric resistance heating elements for times when demand exceeds what the heat pump can produce.

Financial Example

Warranty 6 years 10 years Capacity 40 gallons 50 gallons Retail Price $479 $1,539 Instant Discount n/a -$1,050 Final Purchase Cost $479 $489 Annual Electricity Cost ($/year)* $792 $214 $578

Benefits

They produce lots of hot water. They can save more than $5,000 over the life of the unit compared to traditional electric water heaters. They typically have 10+ year warranties. They help dehumidify.

* Compared to a traditional electric water heater as shown on Efficiency Maine’s Compare Water Heating Costs calculator as of 1/29/2026. Your cost and savings may vary.

Take Action

If your electric water heater is more than ten years old, replace it now while incentives are available. Don’t wait for it to break. Install a heat pump water heater yourself or use our online tool to find a participating installer.

Things to Consider

Because of their noise and cooling effect, heat pump water heaters are better suited to basements than living spaces. They complement, but do not replace, dehumidifiers because they operate based on hot water demand not humidity levels. Condensate from the heat pump water heater must be drained, usually to a sink, drain, sump pump pit, etc. For optimum efficiency, install units in 10’ x 10’ or larger rooms with temperatures above 35°F. Recommended clearances from walls and ceilings should be followed to ensure adequate air circulation and access. Insulate the first few feet of incoming and outgoing pipe to minimize heat loss. Air filters should be rinsed regularly.