What happens if you don't service your tankless water heater?

Author: Ms. Ada Wilderman IV  |  Last update: Tuesday, April 7, 2026

If you neglect maintenance on your tankless heater, it will reduce the lifespan of your investment. You could go years without performing maintenance and the heater will still function. It won't heat the water efficiently, but it will still produce hot water at a reduced flow rate.

Does a tankless water heater need to be serviced?

However, while they may be low maintenance, they do still need to be monitored and serviced by a professional from time to time. It's recommended that you have your tankless hot water heater serviced at least once a year by a professional.

What happens if you don't clean your tankless water heater?

You need to flush a tankless water heater once a year to get rid of mineral deposits and sediment that block the water flow. If you don't, this problem can cause your tankless hot water heater to stop working. You also might void the warranty by not doing it.

How much does it cost to have a tankless water heater serviced?

Common Tankless Water Heater Maintenance Expenses

Labor costs can range from $50 to $150 per hour, while replacement parts can cost between $20 to $500, depending on the part's complexity and brand.

How do I know if my tankless water heater is bad?

To help you identify when you have a tankless water heater in trouble, we've listed several warning signs to watch for:
  1. A drop in hot water pressure. ...
  2. Lukewarm water. ...
  3. The water heater keeps shutting off. ...
  4. Unusual behavior from other appliances. ...
  5. Leaks.

3 Things They Don’t Tell You About Tankless

What is the lifespan of a tankless water heater?

Tankless water heaters usually last for around 15-20 years before they need to be replaced, but they may need replacing sooner if they start to break down or lose efficiency. Some common signs your tankless water heater needs to be replaced include: Low water pressure. Water doesn't get hot.

Do tankless water heaters need to be flushed every year?

Over time, a tankless water heater may accumulate mineral build up which can erode the walls inside your tank's heating chamber. To properly maintain and clean your tankless water heater, it's important to flush those mineral deposits at least once a year.

How much do plumbers charge to flush a tankless water heater?

The average cost to flush a tankless water heater can vary. On average, homeowners can expect to spend between $100 and $300 for a professional flush, including any additional maintenance services required. DIY flushing costs can range from $30 to $100, depending on the flushing kit purchased.

How often should a tankless water heater be replaced?

With proper maintenance, a tank water heater tank should last six to 12 years. A tankless water heater can last for more than 20 years. Check your water heater's warranty for the most accurate timelines.

What happens if you never flush your water heater?

-Reduced Efficiency: As scaling collects at the bottom of the tank, your water heater will become less effective at heating the water in the tank. -Corrosion: If your water heater goes long enough without a proper flush, you could also have corrosion attacking the tank itself, weakening its structural integrity.

Why don t more people use tankless water heaters?

Some people hesitate to decide on a tankless water heater because they can be a slightly higher cost; however, you get significantly more life out of one. A standard water heater tank lasts about 8-12 years. A tankless water heater can last as long as 25 years!

Is it OK to unplug a tankless water heater?

There are no renowned damages that come with turning off the heat supply for your tankless water heater. Turning off your water heater and the main water supply is best for you when you are going for a break.

How do I know if my tankless water heater needs to be flushed?

Common signs it's time to flush or drain your water heater include:
  1. Low water pressure.
  2. Water takes a long time to heat up.
  3. Water isn't the correct temperature or fluctuates.
  4. Noises coming from the tank, such as rumbling or popping.
  5. Sludge or discolored water.
  6. Frequent Repairs.

How often should I flush a tankless water heater with a water softener?

If you have hard water, it is important to descale and flush your unit at least once a year. If you have a water softening system, we recommend performing a flush of the system every 3-5 years.

Do you have to drain a tankless water heater in winter?

Therefore, your system is protected against freezing if the power goes out during cold weather. Drain the Tankless Water Heater: To winterize the unit, manually drain it by turning off the cold-water supply, gas supply, and temperature control. Next, turn off the circuit breaker to the unit.

What maintenance do tankless water heaters require?

To maximize your tankless water heater's performance and service life, it's important to regularly clean or replace the water filter, clean the air filter (for gas units), and descale and flush the system.

Can I use cleaning vinegar to flush my tankless water heater?

Flushing Your Tankless Water Heater

Dump the vinegar from the bucket and close the cold-water service port. Remove the hose and open the cold water shut-off valve to flush any remaining vinegar. Let it run for about 10 minutes before closing the valve.

Can you burn out a tankless water heater?

If a heating element begins to ground out, it will stay on all the time and overheat drastically. Not surprisingly, the result will be painfully hot water – and that's just for starters. With time, the heater element will burn itself out completely. Then you'll have no hot water at all until the element is replaced.

What happens if you don't flush your tankless water heater?

As water flows through your tankless water heater, it will leave behind small amounts of minerals and sediment. Over time, this can create buildup within the unit that may negatively impact the heat exchanger and restrict water flow.

How much does your electric bill go up with a tankless water heater?

How Much Electricity Does a Tankless Water Heater Use? Many people wonder if tankless water heaters increase electric bills. The answer is no — tankless water heaters can save money on your monthly electric bill because they're 8%-34% more efficient than storage water heaters.

Do plumbers recommend tankless water heaters?

Tankless Water Heaters: Tankless water heaters, also known as on-demand or instantaneous water heaters, heat water directly without the need for a storage tank. Plumbers recommend tankless water heaters for their energy efficiency, space-saving design, and endless hot water supply.

What is the average cost to flush a tankless water heater?

Key Takeaways: Tankless water heater flush cost can range from $50 to $1,300, with an average cost of around $600. The maintenance cost is influenced by factors such as the size of the water heater, materials needing replacement, labor costs, and location.

Do you ever run out of hot water with tankless?

If you turn on the shower for hot water, the tankless system will detect the movement of water in the hot water lines and start to apply heat through a heat exchanger to the water. It will keep doing this as long as there is demand – and that means you won't run out of hot water!

How do you know when a tankless water heater needs to be replaced?

Signs you need a new tankless water heater include:
  1. Increased Energy Bills. Tankless water heaters are known to save you money on heating costs. ...
  2. Poor Hot Water Quality. You may notice the hot water isn't the same anymore. ...
  3. Strange Noises. ...
  4. Age. ...
  5. Multiple Charlotte Water Heater Repairs.

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