Many homeowners wait until their water heater fails before shopping for a replacement. Because they are in a hurry to have hot water again, they are often unable to take the time to shop for the most energy-efficient unit for their specific needs. This is unfortunate because the cost of purchasing and operating a water heater can vary greatly, depending on the type, brand and model selected and on the quality of the installation.
To avoid this, you might want to do some research before you are faced with an emergency situation. An informed decision is a good decision when it comes to buying a new water heater.
Know the Types of Water Heaters That are Available
Within the last few years, a variety of water heaters have become available to consumers. The following types of water heaters are now on the market: Your choice could include electric or gas, storage tank or tankless. It is also possible to purchase water heaters that can be connected to your home's space heating system.
Storage Water Heaters
Options are available for conventional storage water heaters--electricity or natural gas. They range in size from 20 to 80 gallons (75.7 to 302.8 litres). A storage heater operates by releasing hot water from the top of the tank when the hot water tap is turned on. To replace that hot water, cold water enters the bottom of the tank, ensuring that the tank is always full. Because the water is constantly heated in the tank, energy can be wasted even when no faucet is on. This is called standby heat loss. Newer, more energy-efficient storage models can significantly reduce the amount of standby heat loss, making them much less expensive to operate.
If you Go Electric
- Generally cost less to purchase than gas water heaters
- Easy to maintain
- Require no combustibles or venting
- Heat water quickly
- Offer high energy factor ratings
If you Go Gas
- Require a slightly larger up-front investment, but usually cost less to operate
- Must be vented outdoors for safety
- Units with sealed combustion or power venting increase safety
- Not affected by power outages (tank-style only)
Tankless Water Heaters
It is possible to completely eliminate standby heat losses from the tank and reduce energy consumption by 20% to 30% with tankless (or instantaneous) water heaters. Cold water travels through a pipe into the unit, and either a gas burner or an electric element heats the water only when needed. With these systems, you never run out of hot water. But there is one potential drawback with demand water heaters--limited flow rate. Typically, tankless heaters provide hot water at a rate of 2 to 4 gallons (7.6 to 15.2 litres) per minute.
- Larger up-front investment
- Excellent option for residences occupied part-time
- Hangs on the wall and frees up floor space
- Provides continuous hot water
- Reduces energy consumption by as much as 30%
- Gas heaters may require venting
- Can be one large unit (whole house) or individual units where hot water is used (point of use)
One drawback with the tankless unit is that if you're using hot water at more than one location at the same time (e.g., showering and doing laundry simultaneously) you could quickly run out. To meet hot water demand when multiple faucets are being used, demand heaters can be installed in parallel sequence or a very large unit to accommodate the whole house.
Criteria for Selection
As with any purchase, balance the pros and cons of the different water heaters in light of your particular needs. There are numerous factors to consider when choosing a new water heater. Some other considerations are capacity, efficiency, and cost. We will post on that next week.