Unleashing a Gas Water Heater Replacement
An important development is taking place in the world of residential water heaters. Our last blog post covered the emergence of heat pump water heaters. Now you can have one without an expensive upgrade to your electrical service.
Chart from U.S. Energy Information Administration
People with a natural gas water heater may wish to replace it for a number of reasons:
The roller coaster of natural gas pricing (see chart above) makes it difficult to budget for utility costs.
They want to use less/no fossil fuels.
They want to reduce their utility costs with a more efficient way of heating water.
These are just three examples of why you might ditch natural gas and opt for an electric water heater. Now there’s a new reason to consider….
Our last blog post introduced the concept of heat pump water heaters and noted they can be incredibly efficient - up to 75% MORE efficient than other means of heating water. As we pointed out, water heating is the third largest use of energy in the American home behind air conditioning and heating so reducing your water heating costs can be a welcome reduction to your utility bills.
What’s Changed?
Gas water heaters don’t require a significant electrical circuit to work. They burn natural gas to heat water and use relatively little electricity. So a home with a natural gas water heater probably doesn’t have a 240-volt circuit available for a new electric water heater.
Heat pump water heaters have been available for years. For example, Rheem has been making them since 2009. The heat pump water heaters were made as a replacement for aging resistance electric heaters - replace your old water heater with a more efficient heat pump water heater.
That worked fine because both were wired to use a 240-volt circuit - something already installed in the breaker panel. A homeowner with a natural gas water heater wouldn’t have that circuit available so a potentially expensive upgrade to the electrical panel would be necessary to convert from natural gas to electric water heating…. until now.
A group of stakeholders has been working since a group meeting in October of 2018 to solve this problem. The result is a heat pump water heater that can be plugged into the typical 120-volt outlet you find in homes.
A New Opportunity
New 120-volt water heaters are a particularly good solution for homes with a low number of occupants or low demand for hot water. The 120-volt water heaters don’t have a quick recovery time because they don’t have a 240-volt electric resistance element to heat water quickly. That’s not an issue if the water heaters are sized correctly so the lack of an electric resistance element isn’t necessarily a bad thing.
The 120-volt heat pump water heaters typically draw up to 15 amps. That’s the size of a typical residential circuit. You’re much more likely to have that spare capacity in your breaker panel than the capacity for a 240-volt circuit like those used for clothes dryers, ovens and cooktops.
New Technology
120-volt heat pump water heaters come in the typical tank sizes: 40, 50, 65 and 80 gallons. They can be an excellent solution for households with 2 - 4 people sharing the water heater or you might use more than one for a larger household.
You can also look for a built-in WiFi module to let you control the water heater and connect to cloud services. Why does that matter?
The connection makes demand management possible. That’s the ability to set your water heater so that it heats water during a window in which your electricity is less expensive - off peak hours.
Some units can also have demand response controls from the utility. That would allow the utility to reduce the amount of power needed or stop water heating while the utility is experiencing peak demand. An example would be the mid- to late-afternoon peak demand for air conditioning in the summer months.
Some units also offer a wireless “vacation” or “away” mode - no more trips to the water heater or forgetting to set the temperature lower before you leave. Some of the units also offer a built-in guard against leaks that shuts off the valve to minimize damage.
Low-Hanging Fruit
Be sure to maximize your investment if you choose to invest in a heat pump water heater. Pipe insulation should be at the top of your checklist. We’re surprised how many homes lack any kind of insulation on hot water pipes.
Hot water pipes without insulation act like a huge radiator. The heat that you’ve just paid to put into the water is lost through the conductive walls of the pipe as the hot water is on its way to your fixture. Pipes are often in spaces like crawlspaces where there’s no benefit from wasted energy.
Also, take a moment to see if your utility offers a rate plan that provides lower costs when you’re heating water. A new water heater with the demand response controls we mentioned earlier can be set to heat water over night to be ready for your shower before school or work. Your overnight rates might be very low if you choose the rate plan that’s best for you.
ProTerra Water Heaters by Rheem are an example of 15-amp units.
Getting Started
There are already a number of the 120-volt water heaters on the market from various manufacturers though our experience is you have to search and ask for them as many people are not aware of them. People still assume a 240-volt connection.
The table above from Rheem is an example - you’d have to notice the last four water heaters are 15-amp units. Their website, like other manufacturers, doesn’t highlight the lower voltage/amperage units so you have to go looking.
So, as with any water heater, find a product family you feel will be a good fit and compare its performance to the needs of your household. Don’t forget, some building/plumbing codes set minimum water heater capacities for houses. Georgia is one of the states with such requirements.
This technology could save you hundreds of dollars each year and thousands of dollars over the life of the water heater. Depending on your use, you may save more than the cost of the water heater over its life compared to other models.
Leave a comment below to let us know if you’re ready for a heat pump water heater in your home. What do you like or dislike? Have you used one? If so, what are your thoughts? Do you have any other questions?