When we opened a door from the kitchen and stepped into the garage during a home inspection on a hot July afternoon recently, it was almost as cool as the rest of the house. Yet the garage was not air conditioned. This was a little puzzling, until we noticed a heat pump water heater in the corner.

    It uses the same technology as a heat pump air internal://conditioner, except in reverse: the water heater was absorbing the heat from the air in the garage and transferring it to the water heater tank. So, in the process of heating water, it was also cooling the room. Because absorbing existing heat is always more energy-efficient than generating new heat, these units are two to three times more efficient than a conventional water heater that uses an electric-resistance heating element, according to the U.S. Department of Energy (DOE). 

    That’s obviously a big savings. So, why is it that we have only seen two heat pump water heaters in over 500 home inspections during the past year? Initial cost is the factor holding back consumer demand, at least for now. We had to look up pricing online because they are not even in stock at the local big-box home improvement stores.

    Heat pump water heaters are called hybrids by retailers because they also have regular heating elements as a back-up system. A 50-gallon hybrid model with a 10-year warranty, manufactured by GE, is currently listed at $999. It is half that price, or less, for a regular water heater. However, the thousand dollar price tag is a big drop from approximately twice that number a year or two ago. So the price is coming down.

    Installation labor by a plumber is the same as a standard water heater, so the cost difference is completely in the price of the unit. As the DOE ratchets up energy efficiency requirements for water heaters every few years—the last up-tick was this April—there will likely be more hybrids manufactured, on the floor in stores, and at even better prices. At least we hope so.

    Heat pump water heaters need to be installed in a location with a temperature range between 40-90ºF year-round. To read more about this new application for heat pump technology, visit the Department of Energy’s website at: http://energy.gov/energysaver/articles/heat-pump-water-heaters.

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Here’s links to a collection of more blog posts about WATER HEATERS:

• Are water heaters required to be raised off the floor? 

• Can a Temperature and Pressure Relief (TPR or T&P) valve be mounted to discharge horizontally?

• Where are gas water heaters not allowed to be installed?  

• Is the minimum size water heater inlet pipe 1/2" or 3/4" according to the building code? 

• Can you use a light switch for a water heater disconnect? 

• How can I tell if a water heater is HUD-approved for mobile/manufactured homes?

• Can you wire a 240-volt water heater with 120 volts? 

• Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater?  

• What is the minimum clearance to doors and windows for an outdoor tankless gas water heater? 

• What is required clearance for access and working space in front of an electric water heater? 

• Why is the water heater older than the house? 

• Does a water heater need a shut-off valve? 

• Why should a tankless water heater have an isolator/service valve kit installed?

• When was a gas water heater first required to be elevated 18 inches above a garage floor?  

• Can the temperature and pressure relief (TPR) valve discharge pipe for a mobile/manufactured home water heater terminate under the home? 

• What is the purpose of a thermostatic mixing valve above a water heater? 

• Does a tankless gas water heater still work with no electricity during a power outage?  

•  Why do water heaters have a sacrificial anode? 

• What is the difference between a manufactured/mobile home water heater and a regular water heater? 

• Does a tankless water heater require a pressure relief valve?

• When is a water heater drain pan required?

   Visit our WATER HEATERS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.