How long does a tankless water heater last?

After spending lots of money, everyone wants a long lifespan appliance. A tankless water heater becomes a daily essential, especially in cold areas, and they should have long durability because its installation cost is very high. So, if you buy any water heater, you must know How Long Does A Tankless Water Heater Lasts? After spending a lot of money, it should have a long life span too.

Otherwise, if you already have a water heater and want to replace it with a highly durable and reliable new heating system. And if your old water heater has some issues or is not enough for your home size.

Actually, no one can afford high investment for on-demand water heaters every two to three years, and you must maintain it to enhance its longevity.

Maintenance is essential for everything. If you want a long lifespan of your tankless water heater to maintain it, then it will last about 15-20 years, and some carelessness can create some issues and minimize its durability. So, here we discussed some main conditions that affect the longevity of your tankless water heater.

Reasons That Minimize Longevity of Tankless Water Heaters

So, make your tankless water heater last for years with total care and maintenance. In addition, here are some reasons that can minimize water heater longevity. We suggest always choosing a tankless water heater because it has a longer lifespan than a tank water heater. Here are a few reasons.

Water Quality

If your groundwater quality is low and you will get hard water, then your appliances will be effective by their quality. It may cause stains and damage the heating rod, and it also affects you throughout the plumping system.  If you are using a tankless water heater, it reduces its lifespan by approximately 3-4 years.


The location of the tankless where you installed it should be right for this. It may perfectly fit near the washroom. But if you install it in garages or crawl, it is hard to flow the heated water to the desired location and not fully heat the water.

Water Issues That Reduce Lifespan

Here we listed common water issues that reduce the lifespan of a water heater. If you face it, be aware and take immediate action. Try to troubleshoot by professional.

Too Hot Water

If you notice your heater provides too hot water that you are not needed. So, please check out its temperature settings which may be accidentally reset, and provide extra hot water. The warm water is usually 49 degrees celsius. 

Plus, also check the thermostat’s functionality. Does it produce accurate temperature readings or not? Sometimes it gives an unexpected reading then replaces it.

Give Unexpected Warm Water

In that case, you may have the opposite issue. If you didn’t get warm water rather than a tankless water heater, flow lukewarm water only instead of a specific fixed temperature, then set it to your thermostats and correct temperature and mount it first.

Otherwise, it’s all Working ok then the problem May be created by heating elements or a dip tube. You should change it and call the best water heater service provider.

Water Heater Leakage

Here on the leakage issue, you may see. If it comes out, leakage from a water heater may occur from several places due to low plumbing systems. Any component replaces it and fixes it. Otherwise, you should check out the pressure relief valve, drain valve, and outlet.

Noisey Tankless Water Heater

Sometimes a tankless water heater is noisy and produces sound when the heating process starts. Like hisses, rumbles indicate the water is too hot or may have pressure and water flow issues. It would be best if you took action immediately. If you don’t pay attention, it may damage the water heater.

Expected Life span

A water heater comes with a 10-15 years lifespan, whether an electric or gas water heater. But if you care for it more and maintain it, then durability will be enhanced. That is about 20 years.

Low Corrosion

A well-made and high-quality water heater never causes stain and rust, but many tanked water heaters have medium material quality according to price in the low price range. It can affect an anode rod, which is made of metal, and it may cause rust and stain and reduce life, replace it every 2-3 years. Otherwise, if you do not replace the anode rod, it may cause leakage.

While if you buy a tankless water heater, you never face this problem because a tankless water heater does not have any tank and has no problem with rust and stains on the rod. Its function is to defer to the tanked water heater. That’s why this has a long lifespan.

Improper Installation

Sometimes if a water heater is not installed properly, that would create some issues in the future, and it’s really serious such as gas leakage and gas explosion if you have a gas or propane water heater. So, we suggest a gas water heater only installed with a professional plumber.

But if you have a tankless electric water heater, you make sure about proper wiring to the whole house and where you connect electricity so that the switchboard works properly. If it’s not well connected, that could be a short circuit and electric fire issue. In both cases, the longevity of the water heater will be minimized.

Why Do Water Heaters Need Maintenance?

The hard water affects both gas and electric water heaters. The hard water has lots of minerals that cause them to build up to where the water flows or where the water is stored. It affects the heating process and consumes lots of energy.

Over time, this could shorten the water heater’s lifespan and require this unit’s heat exchanger. A professional suggests you should descale your water heater at least once a year or more than once.

Descale Water Heater Methods

It’s essential to descale water heaters every year, and this issue usually occurs in tankless water heaters rather than tankless heaters. Please follow this guide, and you can do this yourself without needing any professional help. 

  • It will take approximately one and half hours to complete.
  • First, you must have 4 gallons of descaling solution. You can use white vinegar if other solutions are not available.
  • A big bucket that can hold above 5-gallon solutions.
  • You can also use a professional plumping kit that you can buy from any store, even an amazon online store.
  • After this, before starting the process, be sure to cut the connection of heater gas or electric.
  • Now turn off the water supply, and if you have a tank water heater, then release water from It.
  • Here you need two houses about ¾ inches. Take one hose and connect with the input valve and next connect to the output valve and the end of this hose in the 5-gallon bucket.
  • Now put the vinegar solution into the bucket and place the pump in the bucket.
  • Now turn on the pump and wait for 40-50 minutes until the remaining vinegar drains from the heater and into the bucket before moving on.
  • Rinse water heater with plain water and remove the hose
  • Fix all parts carefully and let them dry for one hour.
  • Now reconnect your connection to electricity or gas and turn on the water heater.
  • Now it will be clean and maintained and can increase longevity and be free of damaging sediment buildup.

How to Increase the Longevity of a Water Heater?

Electric and gas water heaters have 15-20 years of durability when you maintain them and replace some parts, and then it would belong last. Here are some parts that can be replaceable if it’s damaged and with these methods, you can increase longevity.

Average Lifespan Of Water Heater

Water HeaterLongevity
Tanked Gas8-12 years
Tanked Electric10-15 years
Tankless Gas/ElectricAbove 18 years

Need for Repairs

A tankless water heater has more longevity than a tanked water heater, and they do not require regular maintenance. But some necessary repairs help to make long lifespans fewer issues in the future.

Pressure-Relief Valve Working

A water heater has a pressure-relief valve that can handle and control pressure building during the heating process and prevent any explosion. You must check out all the functionality of the pressure relief valve, and if it does not work correctly, you must replace it with a new one.

Anode Rod

The major cause of failure of the tank water heater is anode rod. You must check every year if it is in good condition or not. If it is in bad condition, replace it with a better one that helps to increase the lifespan of the tank water heater. Plus, it will prevent leakages.

Whether you have a gas or electric water heater, they produce desirable temperature water anywhere you want instantly. If you want to enhance its longevity, it should annually flash its rod every three years.

Remove Limescale

Limescale could damage the material and disturb the water heating system. So please flush out all limescale by using a cleaning method. The process was different for both tank and tankless water heaters. Get help from a professional service provider.

Inspect System Setting

Be aware of all settings of your water heater system. Checking all pipelines, flow, temperatures, and especially checking out leakage issues, even a small leak can become a reason for a large explosion.

Related topic:

How does a tankless water heater work?