Tankless Water Heater Pros and Cons

Tankless Water Heater Pros and Cons

In today’s modern world where almost everything is instantaneous, most people are turning to what they deem to be the shortcut to a “quick hot shower” by installing tankless water heaters. These are by far becoming the most popular water heating systems in most homes. However, many do not fully understand the heaters working system as compared to the water tank heating systems. Most believe that since they are instantaneous this translates to efficiency. Here we examine whether or not the heaters are a better option.

Before making the decision of whether to go tankless or not, it is pertinent to understand how they work and their advantages. age I will help you understand in details tankless water heater pros and cons.

Related: Learn How Does Tankless Water Heaters Work

How the Units Heat Water

These units work by heating water instantly without the need of a water tank. You just need to ensure that you have a good flow of water. Tankless heating units utilize various energy sources including electricity, resistance heating coils or gas fired burners using natural gas or propane fuel. When your tap is on, cold water will run through the pipe that is connected directly to the heating unit. The heating units are equipped with flow sensing devices.

These devices are activated as soon as a water tap is opened and the required flow rate is reached. The water is then passed through a copper heat exchanger and a gas or electric element heats up the water. The unit then heats the water to the designated temperature. When the tap is turned off, the gas burner or electrical elements sense that the flow of the water has stopped, and therefore shut down.

The temperature of the water dispelled, however, depends on the flow of water. It is also important to note that this system has a minimum flow requirement before the heater is activated, without which the heater cannot be activated. The traditional water heaters, on the other hand, utilize tanks or vessels with a heater that keeps water continuously hot and ready to use.

Here the all the water in the vessel is heated at a time in preparation for use the amount of hot/ warm water that can be dispelled at any given time depends on the capacity of water that your tank is able to hold. If your tank runs out of water you will have to cool your heels as you wait for the tank water heats up again.  The standard water heater may be electric or fuel-fired.

Related: How to Choose Gas or Electric Tankless Water Heater

Pros of a tankless water heater

Space Convenience

Inarguably, the greatest advantage that the tankless heater has above its counterpart is the efficiency of space. With this kind of heater, one does not need huge tanks for water storage. Traditional water may stand to a height of 60″ tall and width of and 24″ wide. That capacity can take up a lot of space which is a precious commodity in the real estate business. The heaters are small and easy to mount inconspicuously. The tanks can even be installed outdoors.

Unlimited hot water supply

With the tankless water heater, one can almost always be assured that there will always be hot water for a “quick hot shower” provided there is running water. This is unlike the conventional hot water tanks which can supply only as much hot water as the storage capacity of our tank. If your tank runs out, well you will have an extra cost of reheating the water.

Both Electric and Gas Models are Available

Tankless water heaters have various ways in which they can be powered. Some of the heaters in the market are powered using natural gas. However electric models are also available in the market to suit the different preferences. Homeowners may opt to use non-gas units in the market so as to avoid the added costs of alterations in the home.

Related: 5 Easy Steps to Repair Tankless Water Heater

Cost and Energy Efficiency

In comparison to the water tank heaters, the tankless water heaters are considerably more energy efficient. This is because the devices heat water only when needed. They only need enough power to heat the amount of water necessary at any given moment. The traditional tank water heaters, on the other hand, need a constant energy/ power standby supply to keep the water warm. It doesn’t matter your hot water requirements, these heaters can heat and reheat at a given set temperature.

Reduced risk of water damage

Typically, most storage tanks are mounted on flat surfaces including rooftops and basements. It is also common knowledge that spillage of water may easily occur when storing water in large appliances or storage areas. This may happen due to equipment failure of the storage tanks causing immense damage to the surfaces. However, tankless heaters avoid this risk as they don’t actually store water at all. All water dispensed is directly from the water pipes supply.

Cleaner water

Unlike the traditional water tank system, the tankless heater system depends on running water. This greatly increases the cleanliness of the water. In the traditional water tank heater, the water may sit stagnant for extended periods of time causing sediment to build up over time. This may result in contamination of the water. The advantage here is that since the water is never held within the confines of the heater, a cleaner hot water supply for your home is assured. If you want to know how to clean a tankless water heater read here

Longer Lifespan

Another inarguable advantage that the tankless water heater has against its relative is a longer lifespan. A high-quality tankless heater is estimated to last an average of twenty years before needing replacement. However, the water tank heating system is averaged to last half that time. Thus it would be prudent for a homeowner to opt for a water heating system that will last longer and not be replaced every decade.

Property Values

With the dynamic property markets, there is a high turnover in the sale and resale of homes, also the vibrant economy makes people always searching for better living areas. Each new homeowner wants to pay the least amount possible to smoothen his/ her transition. It is a big turnoff for aspiring homeowners to deal with the expenses of high bills and maintenance issues when it comes to the water heating system. Thus most aspiring owners would rather get homes with the tankless heaters which need less maintenance and last longer than the storage water heaters


This is an area where the tankless heater system scores highly because most of the models in the market are fitted with monitoring systems. They give precise details about water pressure and flow. The machines are also manufactured in a way that they can easily detect any system failures and automatically turn off the heater. The fact that they only operate on demand unlike the traditional heaters which are almost permanently on is a plus on the side of safety.

Environmentally friendly

It is needless to say that most the tankless water heating systems are electric. Thus they do not produce any greenhouse gases that are detrimental to the environment. This making the tankless heater systems more environmentally friendly as compared to the water tank heating systems

Tankless water heater cons

Susceptibility to hard water

One of the most common yet least talked about the disadvantage of the tankless heaters its susceptibility to hard water. The heaters are not protected against the lime and mineral build up that often occurs. Hard water affects all water heaters, but it’s especially hard on tankless units. In most areas water used leaves deposits which can clog up the system and affect its function ability. However, such faults are not covered by manufacturer’s warranties.

Upfront cost

Compared to the traditional water heater tanks, the tankless heaters have a higher initial setup cost. The tankless heaters cost averagely twice as much as the traditional tank water heaters. The heaters also need more expertise to install thus more cost for installation. They also have special venting requirements and larger gas lines because of the higher BTU rating. This combined makes the upfront cost costlier than the traditional water tank heaters.

Inconsistent Temperatures

One major complaint that has been consistent is the fact that the water temperature is not always stable. This is may be caused by the fluctuations in the water supply. Thus now and then the water may tend to be hotter or colder as the water is dispelled. In instances where the user dispels through multiple outlets fluctuations in temperature are common because of the heater’s inability to send enough hot water to multiple outlets simultaneously.

Related: List of High-Quality Tankless Water Heaters

Final Words

The above are the major tankless water heater pros and cons. Whether you intend to install or replace a water heating system the choice is dependent on what suits you best. It is recommended to weigh in all the expense factors and potential for problems. It will be wise to read up as much as possible on the specifics of the models available in the market. Scrutinize the cost of operation, water requirements, and manufacturer warranties. In the end, it is up to you to settle on the one that perfectly suits your needs. Buy the water heater that is in line with your water usage, lifestyle situation, and budget.

See also: Tips for Troubleshooting Tankless Water Heater Problems