From traditional tank models to cutting-edge tankless systems, there are numerous water heaters to choose from. Picking the right one can have a big impact on your comfort and energy bills, but it’s not one size fits all. Different water heaters work for different circumstances.
In the video above, This Old House plumbing and heating expert Richard Trethewey breaks down the various water heater types available, exploring their features, benefits, and potential drawbacks. We’ll go into more detail in our guide below.
Gas Storage Tank Water Heaters
Gas storage tank water heaters are the most common in American homes. These units consist of a large insulated tank that stores and heats water using a gas burner located at the bottom.
How They Work
Cold water enters the glass-lined tank through a dip tube, which directs it to the bottom where it’s heated. As the water warms, it naturally rises to the top of the tank through convection. A flue runs through the tank’s center, carrying exhaust gases up and out of the house. This design ensures that the water is consistently heated throughout the tank.
Pros:
- Can provide a large volume of hot water quickly
- Uses familiar technology for most plumbers
- Has a relatively low upfront cost
Cons:
- Is less energy-efficient than newer technologies
- Has a limited supply of hot water (tank can run out)
- Requires regular maintenance to prevent sediment buildup
Tretheway says that these units typically provide about two-thirds of the tank’s capacity in hot water before needing to reheat. However, these heaters are reliable and well-understood by professionals, making them a go-to choice for many households.
Electric Storage Tank Water Heaters
Electric storage tank water heaters operate similarly to their gas counterparts but use electric heating elements instead of a gas burner.
Key Features
- Two heating elements (usually 4,500 watts each)
- No flue required, as there’s no combustion
- Better insulated than gas models, retaining heat more effectively
How They Work
Electric storage tank water heaters use electric heating elements within a large insulated tank to heat and store water. When hot water is needed, it’s drawn from the top of the tank, and cold water flows into the bottom to be heated, ensuring a continuous supply of hot water.
Pros
- Easy to install and operate
- Low installation cost compared to other models
- More efficient at retaining heat than their gas counterparts
Cons
- More expensive to operate due to the cost of electricity versus natural gas in many areas
- May be insufficient for large or high-demand households due to the tank’s capacity
Hybrid Heat Pump Water Heaters
Hybrid heat pump water heaters are a big advancement in energy efficiency for electric water heating. These units are known for their ability to reduce energy consumption while providing reliable hot water.
How They Work
These units combine a traditional electric water heater with a heat pump that extracts warmth from the surrounding air. The heat pump works like an air conditioner in reverse, moving heat from the air into the water tank. This process is highly efficient and can significantly lower energy bills.
Pros
- Can be two to three times more energy-efficient than conventional electric water heaters
- May dehumidify the surrounding area as a beneficial side effect
- Produces fewer greenhouse gas emissions because it transfers heat rather than generating it
Cons
- Works best in warmer climates or spaces
- Require sufficient space for air circulation around the unit
- More expensive to install than traditional electric or gas models
These units have a backup electric element for times when the heat pump can’t keep up with demand. This ensures that homeowners always have access to hot water, even during peak usage times.
Tankless Water Heaters
Tankless water heaters, also known as on-demand water heaters, heat water only when needed, eliminating the need for a storage tank. These systems have become popular because they’re energy-efficient and compact.
How They Work
- A gas burner or electric element heats the water instantly
- Cold water flows through a pipe into the unit when a hot water tap is turned on
- The unit provides a continuous supply of hot water
Pros
- Can provide unlimited hot water (though flow rate my be limited)
- Generally more energy-efficient than traditional tank models because they don’t suffer from standby heat loss
- Are compact and can be mounted on walls or installed in smaller spaces
Cons
- Higher upfront cost compared to traditional tank models
- May require upgrades to gas lines or electrical systems
- Needs regular maintenance to ensure optimal performance
Tretheway says that these units are popular in Asia and Europe and are gaining traction in the United States. They’re ideal for homes where space is limited and for those looking to reduce their energy consumption.
Indirect Water Heaters
Indirect water heaters are a unique option that relies on a home’s boiler or furnace for heat. These systems are efficient and effective, providing hot water without the need for additional burners or heating elements.
How They Work
- Uses a stainless steel-lined tank with a coiled heat exchanger
- Boiler water circulates through the coil, heating the water in the tank
- Connects to a boiler or furnace via pipes
Pros
- Can provide large volumes of hot water
- Highly efficient when paired with a high-efficiency boiler
- No direct flame or heating element in the tank itself
- Reduced risk of sediment buildup compared to direct heating methods
Cons
- Won’t work if your boiler is down or needs maintenance
- May have slower recovery times compared to some tankless models, which can be less efficient for rapid hot water demands
- Is complex to install
These systems are particularly popular in homes with hydronic heating systems because they use the existing boiler to heat water, reducing energy costs and optimizing space.
Solar Water Heaters
Solar water heaters use renewable energy from the sun to heat water. These systems are environmentally friendly and can significantly reduce energy costs over time.
How They Work
Solar collectors, typically installed on the roof, capture solar energy and transfer it to a water storage tank. The heated water is then available for household use.
Pros:
- Uses a renewable energy source, improving your environmental impact
- Can significantly lower energy bills
- Makes you eligible for tax credits and incentives
Cons:
- Is dependent on sunny weather
- Is expensive to install
- Requires adequate roof space for solar collectors
Solar water heaters are ideal for homes in sunny climates and for homeowners looking to invest in renewable energy. Though expensive to install, the long-term savings and environmental benefits can make them a worthwhile investment.
Factors To Consider When Choosing a Water Heater
You’ll need to think about several factors when choosing a water heater for your home, including the following:
- Energy efficiency ratings: Though sometimes more expensive upfront, choosing a more efficient model can save you money over time and reduce your environmental impact.
- Fuel type availability (gas, electric, solar): Think about what’s most accessible and cost-effective for you. if natural gas is readily available, a gas water heater might be best. If you already have solar panels installed or live in a really sunny area, a solar water heater could be a great choice.
- Home size and hot water demand: Bigger homes with higher hot water demand might benefit from larger tank models or tankless systems with higher flow rates. Smaller homes or households with lower demand might do well with compact or on-demand units.
- Initial cost versus long-term operating costs: Some systems may cost more upfront, like more energy-efficient models, but will save you money over time. Alternatively, some models may be cheap to install but more expensive to operate.
- Installation space requirements: The amount of space available in your home may dictate which hot water heaters are feasible to install. Tankless models or compact units might be better for tight spaces, while larger tanks require more room.
- Local climate conditions: Your local climate can impact the performance and efficiency of different water heater types. For example, heat pump water heaters might be less efficient in cold climates due to lower temperatures, while solar water heaters can be really effective in sunny regions.
Maintenance Tips for Water Heaters
Proper maintenance helps your water heater last longer and run efficiently. Follow these maintenance guidelines:
- Adjust the temperature setting for optimal efficiency and safety
- Check the anode rod every few years and replace if necessary
- Clean the exterior of the unit to prevent dust buildup
- Flush the tank annually to remove sediment
- Inspect valves and connections for leaks
- Schedule regular professional inspections
- Test the pressure relief valve annually
Our Conclusion
The right water heater depends on your specific needs, budget, and home configuration. While traditional tank models remain popular, newer technologies such as tankless and hybrid heat pump systems offer significant energy savings. Consider consulting a professional plumber to determine the best option for your home.
