If you’re building a new house, or if it’s time to replace your old hot water tank, you may want to consider looking at a tankless water heater system. These are sometimes called “instantaneous” or “on-demand” water heaters. Instead of constantly heating water and storing it in a tank, these appliances heat up the water only as you need it. They have been common in Europe and Asia for years, but are still fairly new in North America.
How do you know if a tankless heater is right for you?
It’s important to know the pros and cons of a tankless hot water heater before deciding if one is right for your home. Some of the benefits are:
- They last 5 to 10 years longer than tanks.
- They’re compact and take up a lot less space.
- You can save money on your power or gas bills.
- You don’t have to worry about running out of hot water.
Tankless water heaters are, however, more expensive than a hot water tank; up to 3 times as much. They also tend to have a lot more working parts, which could mean more things could possibly go wrong. If you’re looking at an electric tankless water heater, you may need to hire an electrician to ensure you have the right voltage, amperage, and circuit breaker. If you’re looking at a gas model, venting is a concern.
What is a tankless water heater?
We’re all accustomed to seeing the big hot water tank, usually located in the basement. A tankless system looks quite different. They’re small and usually hang on a wall. They come in a couple of different varieties; you can get one that heats all the water for the entire house, or you can get smaller ones at the point of use, for instance, one under the kitchen sink, and one in the bathroom.
With the tank system, a great deal of energy is wasted keeping the water at a constant temperature. This is called “standby heat loss.” You can avoid this with a tankless system.
How does a tankless water heater work?
With a tankless system, the water is heated by a heat exchanger. It uses electric coils or a gas burner to heat the water. As soon as you turn on your hot water tap, the flow of water turns on the heat exchanger, and the water heats up to the temperature you’ve pre-selected. If you’re using a point-of-use system (the small one under the sink); you’ll get hot water immediately. If you’re using a whole house unit, there can be some lag time, as the hot water has to travel a further distance to the faucet.
Tankless heaters can be fueled by electricity, propane, or natural gas. It’s more common to see whole house models fired by gas, with point-of-use models using electricity.
Before you decide to go tankless, you’ll need to consider a few things:
- Flow rate: How much hot water do you usually need? Do you have a large Jacuzzi tub, or several appliances that require hot water at the same time, such as a dishwasher or washing machine? Do you have more than one shower going at the same time?
- Temperature rise: It may seem odd, but the climate where you live has a bearing on how difficult it is to heat the water. What you’re really doing is taking ground water, and heating it to the temperature you want. If you live in a cold climate, and the ground water temperature is very low, it will take longer, and will take more energy, to heat it to the desired temperature.
- Fuel type: What type of fuel will you be using? If you want to heat the water for the whole house, you’ll probably need to use natural gas as a fuel. And you’ll need to ensure that you have an adequate gas supply, which could entail upgrading your gas lines. Electricity should only be used on a smaller heater, such as the point of use ones that fit under your kitchen or bathroom sinks.
The U.S. Department of Energy’s website has an infographic that lists some things to consider when deciding which type of water heater you want to install. And, if you decide to purchase, Tankless Reviews does a good job reviewing different options and prices.
What should you do when something goes wrong?
Here are some common issues with tankless hot water heaters and tips to resolve them:
- Have no hot water: Check to make sure the unit is powered. There may be a red standby light. If it’s not on, a breaker may have tripped. If you reset the breaker, and it’s still not working, call a qualified technician.
- Not as much hot water as before: This could simply be that the ground water temperature has dropped. In the winter, in Canada, temperatures drop significantly. Tankless water heaters normally increase water temperature by 50F. If the ground water is extremely cold, the heater may not be able to warm it quite as much as in the summer.
- When I turn the tap down to get just a light flow of hot water, it turns cold: Most tankless water heaters require .4 GPM (gallons per minute) flow for the heater to come on. If the flow is less than that, the heater shuts off. To fix this, just open your tap a bit more to increase the flow.
- Can’t get enough hot water to fill my tub: If you open the hot water tap all the way, you may be getting too many GPM flowing through the pipes for the heater to handle. Instead, turn the cold part way on, and turn the hot water on enough so it feels nice and hot. You should have no problem filling your tub.
Sometimes problems can be caused by improper installation:
- Venting the exhaust: Tankless systems need a lot of heat to instantly heat the water. The exhaust will also be very hot and needs to be vented quickly. The system monitors the exhaust temperature and will shut down if the venting is slowed by too many turns.
- Scale buildup: if you have hard water in your area, minerals can build up in the heat exchanger. This can result in improper operation or even failure of the unit. The manufacturer may recommend flushing the unit regularly or installing a scale filter.
- High water pressure: If you live in an area with high water pressure, it could be putting stress on your tankless water heater, as well as all of your other plumbing. You may need a water pressure regulator, to avoid premature failure of your water heater.
- Incorrect size: Installing the wrong size tankless water heater is a common problem. Make sure you do the necessary research to ensure you have enough gas, you know how much supply you require, and you place the heater in the right location. Otherwise, you may not have hot water when you need it.
A qualified professional contractor can help you determine the right size and the right location for your tankless water heater.
How can you maintain your tankless water heater?
One thing most experts agree on is that these heaters need to be flushed once a year. You can call a qualified technician to conduct an annual servicing of your tankless water heater.
If your water is quite hard, you might want to install a water softener to help prevent a buildup of calcium. Calcium can reduce water flow, and make your heater less efficient, as well as cause damage to the unit.
If you want to see how a qualified technician can flush a tankless water heater, here is a video by a contractor based in Austin, Texas. This particular unit is installed outside the house, which is unlikely to happen in Canada, but the flushing principle would be similar. Here is another video by the same contractor, on a different make of tankless heater located in a crawl space inside the house.
What is the life expectancy?
Because there is no storage tank, and less risk of corrosion, the life expectancy of a tankless water heater is much greater than that of a regular hot water tank. In general, they last 5 to 10 years longer than a standard hot water tank. If properly maintained, 20 to 25 years is often considered the life span of tankless water heaters.
What will your home insurance provider want to know?
Home insurance providers will want to know the type of water heater you have as well as the age. They may also want to know if it was professionally installed, or if there are any signs of leakage or rust.
Water damage is the cause of many home insurance claims, so insurance providers are understandably concerned about older water heaters. With the storage tank type, there is always the risk of leaking, or even rupturing, causing significant water damage. With a tankless model, there is much less chance of water damage occurring. But of course, even tankless models have a risk of some leakage especially once they pass their life expectancy.
When you’re shopping for home insurance, be sure you know the type, age, and condition of your water heating system. This will help you get a speedy and accurate quote, as rates may vary based on these factors. For more information, or to get a quote on your home insurance, contact Square One at 1.855.331.6933.