How much should it cost to flush a tankless water heater?

Author: Anya Osinski  |  Last update: Saturday, February 28, 2026

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 much does it 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.

Can I flush my own tankless water heater?

A tank heater is very easy to flush, you just need a garden hose, drain it fill and check anode rod. A tankless is also easy to flush, you will also need a pump and a bucket.

How much do plumbers charge to flush a water heater?

The national average cost to flush a water heater is $160, but prices can vary in increments based on the tank size. A 30-gallon tank will cost between $90 and $120 on average, while a 70-gallon tank could cost anywhere between $180 and $250.

How often does a tankless water heater need to be flushed?

Just like a tank unit, tankless water heaters need to be flushed once per year. Homeowners with hard water should consider flushing and cleaning the unit even more frequently, perhaps every six to nine months because of the excess amounts of magnesium and calcium found in hard water supplies.

Tankless water heater flush cost

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.

How much does tankless water heater maintenance cost?

Average Cost of Tankless Water Heater Maintenance

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.

How often should I replace my anode rod?

Anode rods require routine inspection and replacement, approximately every three to five years. Without proper maintenance, the anode rod loses its ability to divert damaging particulates from your tank and can accelerate rust and corrosion from chemical reactions, excessive heat, and imbalanced pH levels.

How much does it cost for a plumber to check a water heater?

If so, you're probably wondering how much a maintenance visit will cost you. The cost of water heater maintenance ranges from $75 to $300+, depending on the following factors: What the plumber checks during a maintenance visit. Whether you choose a single visit or an annual maintenance plan.

Can I flush my water heater myself?

You can flush your water heater yourself if it's done on a regular basis. This guide will take you through the steps to drain and flush a gas or electric water heater. Learning how to clean a water heater is an essential part of maintaining your plumbing system.

What is the best chemical to flush a tankless water heater?

Use 4 gallons (15.1 liters) of undiluted white vinegar to clean your tankless water heater. Never use chemical solutions of any kind. Since your home's drinking and bathing water mostly likely flows through your tankless water heater, using chemical cleaning solutions could be extremely harmful to your health.

What maintenance is required for tankless water heaters?

The most complicated and time-consuming tankless water heater maintenance is typically descaling and flushing out the unit. Even with the inline water filter, lime and calcium deposits can build up inside the tankless system. If you have hard water, it's a good idea to descale and flush the unit once a year.

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.

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.

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

The cost to service a tankless water heater is $600 on average, but it can cost between $75 and $1,300, depending on the type and scope of the repair. 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.

How long do tankless water heaters last?

One of the most common questions asked by consumers about tankless water heaters is how long they will last. A tankless water heater can last anywhere from 15 to 20 years with proper maintenance and operation. In comparison, a standard tank water heater normally has a working life of 10 years or less.

How much does it cost to have someone flush your water heater?

Flushing a tank water heater costs $75 to $150, while tankless water heaters cost $150 to $250 to flush. The cost of flushing a water heater depends on the tank size, type of water heater, labor costs, and additional tasks performed by the plumber.

Are tankless water heaters worth it?

Advantages and Disadvantages of Tankless Water Heaters

The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset their higher purchase price.

How much does it cost to replace a 40 gallon water heater?

Naturally, tanks that heat more gallons of water typically have a higher price point, so the larger the tank size, the more you can expect to pay. For example, the average 40-gallon water heater installation cost runs between $1,000 and $2,500, while its 80-gallon counterpart runs between $2,650 and $3,910.

How much does a plumber charge to replace an anode rod?

An important part of your water heater, it moves cold replacement water to the bottom of the tank when you use hot water; otherwise, both will mix and reduce the water temperature. Anode Rod Replacement: While an anode rod costs between $20 and $50, a plumber can replace it for $50 to $150.

What happens if you don t replace the anode rod in water heater?

The anode rod attracts corrosive elements, such as oxygen and hydrogen sulfide, which would otherwise corrode the walls of your hot water tank.

How do I know if my water heater anode rod is bad?

rust-coloured hot water – that smells – is a classic sign of actual, and serious, tank corrosion. With a bit of luck, it's the corroded and rusty anode rod that's discolouring your water and making it stink and taste weird. Either way, you do need to call your friendly local plumber before that tank is completely shot.

How much does it cost to flush my 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.

What is the recommended maintenance for a tankless water heater?

To maintain your tankless water heater, we recommend cleaning the water inlet filter every few months. Doing so can prevent clogs and keep your hot water flowing smoothly. When removing the water inlet filter, keep an eye out for any leaks, connection seal issues, and damaged parts.

Do tankless water heaters have a lot of problems?

Tankless water heaters are energy-efficient, have low maintenance costs, and are reasonably durable. But just like any appliance, they're not completely immune to issues. From time to time, they may present with minor problems, such as having no hot water, or not firing.

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