How much does it cost to flush a water heater?
Ashburn, VA

How much does it cost to flush a water heater?

Ashburn, VA

How much does it cost to flush a water heater?

$75 – $150 average cost to flush a standard water heater
$150 – $350 average cost to flush a tankless water heater

Get free estimates for your project or view our cost guide below:

$75 – $150 average cost to flush a standard water heater

$150 – $350 average cost to flush a tankless water heater


Get free estimates for your project or view our cost guide below:
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Tamatha Hazen
Written by
Tamatha Hazen
Edited by
Kristen Cramer
Fact-checked by
Tara Farmer

Cost to flush a water heater

The cost to flush a standard water heater ranges from $75 to $150, while flushing a tankless water heater costs $150 to $350. For DIY flushing, the supplies typically cost $10 to $20. Regular water heater maintenance, including flushing, is essential for optimal performance and longevity.

Cost to flush a water heater by type
Water heater type Average cost
Standard water heater $75 – $150
Tankless water heater $150 – $350
DIY flushing $10 – $20

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Water heater flush cost by tank size

The size of your water heater tank can influence the cost of flushing it, as larger tanks take longer to drain and flush. For example, an 80-gallon tank takes 30 to 60 minutes to fully drain and flush, compared to 15 minutes for a 40-gallon tank. With plumber rates of $45 to $150 per hour, that extra time adds up.

Water heater flush cost by tank size
Household size Water heater capacity
(gallons)
Average cost to flush
1 ­– 2 people 30 – 40 $75 – $120
2 – 4 people 40 – 50 $120 – $150
3 – 5 people 50 – 60 $150 – $180
5+ 60 – 80 $180 – $250+

Cost factors to flush a hot water heater

The main factors that affect the cost of flushing a hot water heater include:

  • Water heater type: A standard water heater costs less to flush, as the process is relatively straightforward. A tankless water heater costs more for descaling to remove mineral buildup.

  • Water heater size: The longer time required for larger tanks translates to higher labor costs.

  • Severity of sediment buildup: Water heaters in areas with hard water tend to accumulate more sediment over time. This requires more time and effort to flush thoroughly, increasing the cost.

  • Location & accessibility: Water heaters located in tight or hard-to-access spaces may require more time and specialized equipment to flush, driving up labor costs. Also, professionals traveling to remote locations incur more travel time and expense.

  • Labor rates: Plumber labor rates vary significantly by geographic location, with higher costs in urban areas and lower costs in rural areas. The plumber's experience and expertise can also impact the hourly rate.

  • Repairs: If the plumber identifies any other issues during the flushing process, such as leaks or malfunctioning parts, the water heater repair cost increases your total expense.

Plumber repairing water heater and flushing the tank
Plumber repairing water heater and flushing the tank

Cost to flush a tankless water heater

The cost to flush a tankless water heater is $150 to $350. The process is more involved for tankless heaters due to their complex design and susceptibility to mineral buildup. The descaling process involves using a pump to circulate a descaling solution through the heater to remove stubborn deposits.

DIY water heater flush cost

The DIY cost to flush your own water heater is mainly for the time and effort it takes, as the actual supplies only cost $10 to $20. While the process seems straightforward, there are risks if not done properly. Hiring a professional ensures the job is done safely and effectively, especially for tankless models.

FAQs about flushing a water heater

How do you flush a water heater?

Plumbers flush a water heater by attaching a hose to the drain valve and draining the tank. Once empty, they attach a supply hose to refill the tank with fresh water. The new water circulates and flushes out any sediment buildup. The plumber continues flushing until the draining water runs clear, indicating the tank is clean.

A thorough flushing process helps remove damaging buildup and increase the water heater’s efficiency and lifespan.

How often should you flush your water heater?

Most experts recommend flushing a water heater at least once per year. However, for homes with hard water, flushing every 6 months is ideal, while those with soft water may only need it every 2 to 3 years.

Why should you flush your water heater?

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You should flush your water heater to remove sediment buildup that can damage the tank and components over time. Routine flushing can increase the lifespan of the heater, improve energy efficiency, reduce recovery time, and eliminate noises. Your manufacturer's warranty may also require it.

Getting quotes from plumbers for water heater flushing

To find the right water heater repair service or plumber to flush your water heater, follow these suggestions:

  • Request quotes from multiple local plumbers with positive reviews on HomeGuide and Google.

  • Inquire about the plumber's expertise and training for properly flushing water heaters.

  • Ask about any additional repairs or services.

  • Get a full inspection and address any underlying problems to save money later on.

  • Schedule during the off-season for better prices and availability.

Questions to ask a plumber

Ask a plumber near you these questions before scheduling a water heater flushing service:

  • How often do you recommend flushing a water heater?

  • What is your process for flushing a water heater?

  • Do you have experience flushing my specific type of water heater?

  • What are the benefits of regular flushing?

  • How much will it cost to flush my water heater?

  • Do you offer any warranties or guarantees on your work?

  • How can I prevent sediment buildup between flushes?