Water Filter IQ

Weighing the Pros and Cons of a Tankless Water Heater

There is nothing more frustrating than wanting to get a nice, hot shower and finding out that everyone has used the hot water. The reason this happens is because conventional hot water heaters only heat a certain amount of water at a time. Once this water is used up, you have to wait for the heater to generate more hot water. It can take a few minutes or much longer depending on your tank.

One way to get around this problem is to install a tankless water heater in your home. The way a tankless water heater works is quite simple. The water is stored as cold water. When you turn on your hot water faucet, the water travels through a pipe. The water is heated with either a gas burner or an electric element to heat the water as it travels through the pipe.

Because the water is heated as it goes through the pipe, there is a constant flow of hot water to your taps. You never have to wait for the tank to fill up with hot water because there is no tank. The water constantly flows through and is heated on an as-needed basis.

Tankless water heaters produce between 1 and 10 gallons of hot water per minute (GPM). Electric tanklesss water heaters tend to produce less GPM than gas powered units. So, although you will get constant hot water, you won’t get it with the same high pressure as you do with a tank. So, you do need to keep in mind that if you are taking a shower while someone else is in the house doing dishes, you may run out of hot water.

One way to combat this problem is to install multiple tankless water heaters in your home. You can also install separate heaters for different appliances. For example, you can have one tankless water heater attached to your laundry machine while another is hooked up to your shower. This eliminates the problem of water coming from different sources at the same time.

The major benefit of a tankless water heater is that your utility bill will be much lower than with a conventional hot water heater. This is because you don’t have an appliance running constantly to keep the reserve of hot water hot. A lot of countries, such as Europe and Japan have been using tankless hot water heaters for quite some time. They haven’t caught on as quickly in the United States for some reason.

Pros and Cons of a Tankless Water Heater

Whether you install a tankless water heater in your home is not is a matter of personal preference. There is no science behind either appliance that makes it better or worse for your family. Cost wise, there is not going to be much of a difference either way. The money you may save on gas or electric will be offset by the cost of the water heater.

So, what are the pros and cons to a tankless water heater?


Size – A tankless water heater is much smaller than a conventional water heater. You won’t have to worry about a huge hot water heater taking up an entire section of your laundry room or utility room. Tankless water heaters get mounted to the wall so you can pretty much keep it out of the way.

Lower Energy Consumption – Because you don’t have to constantly heat the water in a large tank, you save a lot of money on utility bills. They actually use about 30-50% less energy than a regular tank so you save about $100 per year. Again, as pointed out earlier, this savings is not all that significant, but it is a savings.

Constant Flow – With a tankless water heater, you get a constant flow of hot water. This is ideal for filling up a tub or taking an extra-long shower. You don’t have this with a traditional hot water heater.

Longer Life – Tankless water heaters last than the conventional type of water heater. Most come with a warranty of 12-15 years whereas other water heaters only come with a 6-year warranty. Not only does this mean you’ll have a longer warranty, but you’ll also avoid the inconvenience of having to buy and install a new water heater every 5-6 years.

Accidents – With conventional hot water heaters, there can be nightmare stories of them leaking and destroying people’s carpets, floors and personal belongings. With a tankless water heater, you don’t have this problem at all. The problem with the tanks on regular water heaters is that the leak usually starts out slow and by the time you notice there is an issue, you have a slightly flooded utility room, a wet floor and possible mold issues.


Upfront Cost – The initial cost for at tankless water heater may be the biggest drawback to a tankless water heater. You can buy a smaller unit, but they usually are only good to heat water for one appliance. So, your choice is to either buy several tankless water heaters for your home or buy the larger one. You are really paying for the convenience of always having hot water. And you may make up some of this upfront cost with a reduced utility bill over the life of the appliance.

Limit on Water Delivery – Although you do get a constant stream of hot water, tankless heaters do offer only a limited supply of hot water at any given time. As we mentioned in the description earlier, tankless water heaters can only deliver about 3-5 gallons of water per minute. So, depending on what you are doing, you may not have enough water at all times. One way to avoid this is to install a reservoir tank that can hold the water that has already been heated rather than have this water be processed all over again. This can increase the incremental flow of hot water to your faucets.

Special Venting – Because the tankless water heaters have high-powered burners, they also have special venting requirements. You need to install a dedicated, sealed vent system to meet these special requirements. This does have to be done by a professional. For a gas burner unit, you will need to have an extra-large pipe installed at the time you get the tankless water heater.

Hard Water Issues – The buildup caused by hard water (limescale, mineral and scale) can destroy tankless hot water heaters. This residue and buildup make it hard for the water to be sent through the tubes. This is how the water is heated so if it is stopped up, you are going to run into issues. Keep in mind, warranties do not cover issues caused by hard water. You may want to install a water softener before you switch over to tankless water heaters.

Cold Water Spots – Because the hot water is constantly flowing through the pipes, you can end up with what’s referred to as a cold water “sandwich.” This is when pockets of cold water make their way through the pipes and cause a not so pleasant surprise, especially when you’re showering. However, these are a minor inconvenience in the big scheme of things.

The Verdict

Just like any other change in your home, switching over to a tankless hot water heater system is a personal choice. Financially, there is no major difference when you take into account the initial costs of installing a tankless water heater system. It comes down to how much you value a constant stream of hot water.

If you have a lot of people in your household, it makes sense to install one or maybe several tankless water heaters throughout your home. The small units are less expensive and can solve the problem of having multiple people using hot water at the same time.

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