Make Your Water Heater More Efficient
Water heaters can save big
Improve your water heater's efficiency by insulating the pipes, using an insulating blanket, lowering the water heater temperature to 60ºC or installing a high-efficiency water heater.
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. If you have an old inefficient heater, replacing it with a more efficient unit will bring you the most long-term savings.
Some energy-efficient models may cost more up front, but you'll see energy savings for years to come.
Because water heating uses so much energy, it's an opportunity for big energy savings. Decreasing energy use can help reduce energy peak loads, thereby postponing or preventing the need for additional energy generation and distribution infrastructure, such as: dams, coal-fired power generation stations, and underwater electrical cables.
What you need to know
- Your biggest opportunity for savings is to use less hot water.
- 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.
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.
- 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 an extended period of time (a month or longer), consider turning the thermostat down to the lowest setting, or completely turning off the water heater and draining the tank. It's important to empty and refill the tank if it's been off for an extended period to eliminate bacteria, and to run water to empty the pipes. 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.
- 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
- If your hot water tank is warm to the touch, it's leaking heat. Investing in a new, increased efficiency hot water heater or another water heating option is likely a good option.
- 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 get vented out, so less heat is lost out of the tank.
- The advantage of on-demand water heaters, or tankless gas heaters, is that you heat your water as you use it rather than paying to have it constantly heated in a tank, thereby saving on the standby energy losses associated with conventional storage water heaters. Savings on a natural gas on-demand water heater can be up to 30% compared with a natural-gas storage tank water heater.
- Note that the draw currently required by electric on-demand heaters exceeds the Electric Tariff; so tankless electric systems cannot be used by BC Hydro customers until the technology improves.
- An on-demand water heater, heats cold water using a heating element (heat exchanger) that is turned on by a flow-activated switch.
- Consider your overall water usage when deciding about an on-demand water heating system. 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 small tankless heater to the 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's just as efficient to use a well-insulated conventional electric water tank.
- Note that some tankless water heaters require a minimum flow before any heating occurs, which means that for short draws the water may not be hot. This can result in water waste as users run water to meet the minimum flow.
What are the most important things to consider when selecting a water heater?
Consider the following to determine the right type and model of water heater for your home:
- Fuel type. 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 an appropriately sized water heating system.
- 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.