Improve Your Water Heater’s Efficiency

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Quick Facts Affordability Cost Savings CO2 Reduction		Water heating is the second-largest energy user in the average home. In addition to adopting water-saving technologies and implementing the no-cost tips from this guide to reduce overall water use, homeowners can improve their water heater’s efficiency by insulating their pipes, using an insulating blanket, lowering the water heater temperature to 60ºC or installing high-efficiency water heaters. Affordability Improving your water heater’s efficiency can be as easy as turning down your water heater thermostat (no lower than 55ºC and no higher than 60ºC) and insulating your pipes. Often replacing your water heater with a more efficient unit will bring you the most long-term savings. Cost savings Replacing your traditional water storage heater with a solar water heater can add up to significant long-term savings. One homeowner in North Vancouver, who installed a solar water heater, reported a savings of up to $103 per year on their energy bill. Environmental considerations Solar water heating typically offsets fossil fuel combustion, reducing greenhouse gas emissions and other pollutants. Systems can help reduce peak loads, thereby postponing or preventing the need for additional baseload energy generation and distribution infrastructure, such as new hydroelectric dams, coal-fired power generation stations, and underwater electrical cables.

What you need to know

Minimize operating costs

Conserve water

• Your biggest opportunity for savings is to use less hot water.

Insulating your pipes

• Insulate your electric hot water tank and pipes to minimize heat loss. Improving the insulation on your electric hot water tank and pipes is an easy way to save energy.
• Insulate your hot water pipes. Insulating your hot water pipes will reduce heat loss and may even allow you to slightly reduce the temperature setting on your hot water tank.

Put an insulating blanket on your tank

An insulating blanket is affordable and relatively easy to install.

• The easiest way to find out if your tank could use extra insulation is to place your hand on the outside of it. If the tank is warm to the touch, it is losing heat (for storage water tanks, this is referred to as standby heat loss). If the tank is cool to the touch, you likely wouldn’t benefit by adding extra insulation to your tank. If you have a newer hot water tank, you probably don’t need to wrap it because they are usually well-insulated.
• A gas-fired hot water tank should be wrapped by a heating professional. An insulating blanket can be effective on a gas-fired hot water tank, but it must be carefully installed. The top, bottom and burner compartment of the tank must all be kept clear. If the blanket slips, it could create a health hazard.

Lower your water heater temperature to 60°C

• Keeping your water heater thermostat no higher than 140°F (60°C) can also help to reduce hot water costs. Reducing your water temperature to 140ºF also slows mineral buildup and corrosion in your water heater and pipes. This helps your water heater last longer and operate at its maximum efficiency.
• Consult your water heater owner's manual for instructions on how to operate the thermostat. You can find a thermostat dial for a gas storage water heater near the bottom of the tank on the gas valve. Electric water heaters, on the other hand, may have thermostats positioned behind screw-on plates or panels. As a safety precaution, shut off the electricity to the water heater before removing/opening the panels. Keep in mind that an electric water heater may have two thermostats – one each for the upper and lower heating elements.
• Mark the beginning temperature and the adjusted temperature on the thermostat dial for future reference. After turning it down, check the water temperature with a thermometer at the tap farthest from the water heater. Thermostat dials are often inaccurate, so several adjustments may be necessary before you get the right temperature.
• If you plan to be away from home for at least three days, turn the thermostat down to the lowest setting or completely turn off the water heater. To turn off an electric water heater, switch off the circuit breaker to it. For a gas water heater, make sure you know how to safely relight the pilot light before turning it off.
• Do not lower your water heater temperature below 55ºC to avoid the risk of developing harmful bacteria in your water system. The B.C. Building Code mandates that direct hot water equipment that is capable of heating to at least 45°C but not above 60°C shall be installed.

Additional water heater maintenance tip

• After consulting your hot water tank owner’s manual, drain off a dishpan full of water from the clean-out valve at the bottom of your hot water tank to control sediment and maintain efficiency.

Taking it further

Purchasing a higher efficiency water heater

Often, the best solution to save money and energy is to purchase a new water heater. In addition to the conventional storage tank water heater, there are several new higher efficiency technologies available. Take advantage of the various incentives offered to switch to a more efficient unit.

Solar water heaters

• Consider installing a solar water heater. Solar hot water technology has the potential to be widely used in homes and businesses across B.C. A solar hot water system can meet approximately 50% of total hot water needs. Domestic solar hot water systems reduce the peak loads on electricity or gas heaters and can reduce the demands on utility infrastructure.
• Domestic solar hot water systems are designed to last 20 to 40 years, minimize environmental impacts and promote community economic development through the building of a sustainable economy.
• SolarBC offers a comprehensive $1,625 incentive program for the installation of a solar hot water system for your home.

How do solar hot water systems work?

• The supply of solar energy comes from radiation generated by the sun rather than just visible sunlight, so even cloudy days provide enough energy for a solar hot water system to be effective. In B.C., some seasonal heating loads can be met by solar alone. During winter months and on cloudy days, a solar heating system typically operates as a pre-heater in conjunction with a conventional hot water system.
• Solar hot water systems convert sunlight into heat through solar collectors mounted on the roof. Water, or a water/antifreeze solution, carries heat from the collectors and pumps it through a heat exchanger to a tank for storage and subsequent use. A typical system requires up to six square metres of roof space for collectors and a sloped, south-facing collector orientation is ideal for installation with minimal shading from nearby trees or buildings.

Natural gas on-demand water heater

• The advantage of on-demand water heaters is that you heat your water as you use it rather than paying to have it constantly heated, thereby saving on the standby energy losses associated with conventional storage water heaters. Researchers have found savings can be up to 30% compared with a standard natural-gas storage tank water heater.
• There are basically two types of on-demand water heaters: gas and electric. Gas units are the most efficient choice as they generally have more heating capacity and the larger whole-house (vs. point-of-use) units are typically gas fired. Even though electric models have a higher energy factor than fuel-burning models, electric resistance is a very expensive way to generate heat. Electric models do not have great environmental benefit as they have the potential of greatly increasing peak electricity demand and are therefore not recommended.
• The way an on demand water heater works is when cold water enters the unit and is heated by a heating element (heat exchanger) that is turned on by a flow-activated switch.
• A key factor to consider when making this decision is your overall hot water usage. Some smaller tankless water heaters cannot supply enough hot water for simultaneous, multiple uses in large households. For example, taking a shower and running the dishwasher at the same time can stretch a tankless water heater to its limit. To overcome this problem, you can install a “whole house” type tankless water heater, or install two or more tankless water heaters connected in parallel for simultaneous demands of hot water.
• You can also install separate tankless water heaters for appliances, such as a clothes washer or dishwasher that use a lot of hot water in your home, but there comes a point where it is just as efficient to use a well-insulated conventional electric water tank. While they operate only briefly when heat is needed, additional gas is used in the start up and shut down cycle (and for the pilot in less efficient standing pilot models). They currently have a maximum efficiency of around 80%.
• As a rule of thumb, tankless hot water units make sense in smaller demand units, particularly where there is no bathtub, but rapidly lose efficiency as hot water demands become greater.

Condensing water heater

• Condensing hot water heaters are the most energy-efficient tank-style water heater and thus cost less to operate. In simplest terms, a condensing hot water heater recaptures the heat of the flue gases that normally just get vented out so less heat is lost out of the tank.  Condensing gas water heaters are increasingly popular, especially given the recent trend of rising gas prices.

Improving energy efficiency

After your water heater is properly installed and maintained, try some of the additional energy-saving strategies in this guide to help lower your water heating bills, especially if you require a back-up system. Some energy-saving devices and systems are more cost-effective to install with the water heater.

FAQ

What are the most important things to consider when selecting a water heater?
When selecting the right type and model of water heater for your home, you should consider the following:

• Fuel type, availability and cost – The fuel type or energy source you use for water heating will not only affect the water heater's annual operation costs, but also its size and energy efficiency.
• Size – To provide your household with enough hot water and to maximize efficiency, you need a properly sized water heater.
• Energy efficiency – To maximize your energy and cost savings, you want to know how energy-efficient a water heater is before you purchase it.
• Costs – It's also a good idea to estimate its annual operating costs and compare those costs with other energy-efficient models.

With all of the rain we get in B.C., is a solar hot water system a good choice?
Solar hot water is a growing industry around the world and not just in sunny, tropical climates. Japan and Germany are currently world leaders in solar markets, yet our B.C. climate shows greater solar potential than both Tokyo and Berlin. In fact, the solar potential in Vancouver is only slightly less than that of Miami, Florida. Miami has greater consistency of solar potential from month to month, however taken across a whole year, Vancouver’s annual daily average solar energy production is only 8% less.