Heat Pump Water Heaters

A new concept in Water Heating is the Heat Pump Water Heater. These energy efficient units heat the water using a small heat pump or by using the electric elements only when needed. The same technology as a heat pump heats a home, this smaller version is used to heat the water inside the tank.

Heat pump water heater

Save money.

  • Cut water-heating energy consumption by 50% compared to a standard electric water heater.
  • See up to a 10% reduction on your household electricity bill.

Requirements and Specifications:

  1. Only new construction and existing single family AND manufactured homes qualify for the heat pump water heater (HPWH) reimbursement. In existing homes, the HPWH must replace an electric storage water heater on a one-to-one basis.
  2. HPWHs must be (1) Must be listed on BPA’s HPWH Qualified Products List found here and (2) installed, according to manufacturer’s specifications.
  3. City of Milton building permit is required – Building Dept Info.


Unitary Heat Pump Water Heater Tier 2-3 (All sizes)

$500 Unitary Heat Pump Water Heater Tier 1    (All sizes)

$300 Split system

$700 (interior storage tank + outdoor system)

Split-System HPWHs must meet the following qualifications:

  • Listed on BPA’s HPWH Qualified Products List;
  • Installed according to manufacturer’s specifications;
  • All water or refrigerant lines connecting the tank and outdoor units shall be insulated with minimum R-4;
  • If domestic hot water pipes outdoors are freeze-protected with heat cable, the cable shall be installed per manufacturer’s instructions, underneath the insulation, and shall be thermostatically controlled to prevent the tape from operating above 38°F;
  • No resistance heating is allowed (except heat tape for freeze protection);
  • System plumbed with a thermal mixing valve, which is equipped with internal check valves on the hot and cold water lines connecting to it.