What is the upkeep on a tankless water heater?

Author: Freeman Reinger  |  Last update: Wednesday, April 23, 2025

Generally, tankless water heaters should be serviced once a year; however, they may require more frequent maintenance if you have hard water or if you keep your water temperature high.

Do tankless hot water heaters need maintenance?

It doesn't matter if you have a tank or tankless water heater; your water heater must be maintained. In fact, scale will build up to a foot or thicker inside a tank in just a decade. Tank and tankless manufacturers both recommend regular flushing.

What is the downside of a tankless water heater?

Before you commit to buying a tankless water heater, the primary drawbacks to know include: Higher upfront costs. Tankless water heaters are, on average, quite a bit more expensive to buy and install than tank water heaters. Access to fuel.

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.

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

What happens if I don't flush out my tankless water heater? Mineral deposits may build up. This could cause a clog within the unit and may prevent normal heating activity. Your hot water could also fluctuate and overheat the system, impacting its efficiency.

Tankless Water-Heater Maintenance

What is the average cost 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.

Can I flush my own tankless water heater?

With the right tools and knowledge, you can certainly flush a tankless water heater by yourself. In fact, there are water heater flushing kits you can buy online for the job, which come with everything you need. They include things like a circulation pump, hoses, a bucket and a cleaning agent.

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!

How much is annual maintenance for tankless water heater?

The average cost of maintaining a tankless water heater in the United States ranges between $100 to $500 per year. However, the total cost can vary depending on various factors, including the age of your unit, its condition, and the type of maintenance required.

Can you run out of hot water with a tankless water heater?

You can't run out of hot water with tankless water heaters – unless, of course, the power supply is off or goes out. However, a tankless water heater can have trouble keeping up with demand if too many things require hot water all at once.

Is there an IRS tax credit for a tankless water heater?

The federal tax credit for tankless water heaters can lead to significant savings for homeowners. Eligible tankless gas water heaters must have an ENERGY STAR certification and a UEF of greater than 0.95. Homeowners can claim up to $3,200 in tax credits for eligible home improvements in a single year.

Can I replace my 40 gallon water heater with a tankless water heater?

Absolutely! In fact, tankless water heaters are becoming the standard for new home construction because of the energy efficiency.

Can you take a long hot shower with a tankless water heater?

While a tankless water heater will deliver an unlimited stream of hot water, they struggle to deliver a lot of hot water at one time. So while you might be able to take 100 showers in a row if you have the dishwasher, washing machine, and shower going at the same time you might have problems.

Why avoid a tankless water heater?

Additional Installation Costs

Tankless water heaters are much more complex than traditional hot water tanks. As a result, they require professional installation. If you're switching from a hot water tank to a tankless unit, you will likely need your gas lines rerouted, as well as a larger gas supply line.

How often should a tankless water heater be flushed?

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 long does it take to service a tankless water heater?

Flushing your tankless heater is a simple task, but it does take 1-2 hours to complete. For most water quality, completing this task once a year will suffice, but if you have especially hard water you may want to complete more often.

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

This is because they are more complex than traditional water heaters and may need more frequent flushing to help curb limescale and sediment buildup. As such, you'll spend anywhere between $150 and $250 on average to flush your tankless water heater.

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.

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.

What is the downfall to a tankless water heater?

A tankless water heater cannot provide hot water faster than its ability to heat the water. While a tank unit can provide hot water for multiple uses at once, a tankless unit might not be able to support simultaneous usage, such as washing dishes, taking a shower and running a washing machine all at once.

How many showers can a tankless water heater run?

To find the correct capacity, add up all of the fixtures that you expect to use at the same time. For example, if you know that two people will be showering while another person runs a sink, you would need a 5.75 gpm unit, based on two 2.5 gallon-per-minute showers and one 0.75 gallon-per-minute faucet.

Can you replace a 50 gallon water heater with a tankless water heater?

A 50-gallon water heater should be replaced with a tankless system with a 10 GPM flow rate just to be safe. Selecting the right flow rate ensures you won't experience cold showers or excessive energy costs. Proper sizing optimizes performance, providing hot water on demand without unnecessary waste.

What is one disadvantage of a whole house tankless water heater?

As we discussed above, the biggest downside of owning a Tankless Water Heater is its higher cost. The initial installation costs and the price of the unit are more expensive than a traditional Storage Tank Water Heater. Another downside of a Tankless Water Heater is that it has limited hot water.

How much does it cost to service a tankless water heater?

The cost of maintaining your tankless hot water heater can range from as little as $75 and up to $1,300 for more extensive repairs. On average, the cost to service tankless water heaters is $600. A water heater is an essential part of every home, but you may not appreciate it until it suddenly stops working.

What happens if tankless water heater is not flushed?

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.

Previous article
Are you supposed to hammer in wall anchors?
Next article
Do you sand after skim coat?