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

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

Ashburn, VA

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

$150 – $350 average cost (tankless water heater)
$75 – $150 average cost (standard water heater)

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

$150 – $350 average cost (tankless water heater)

$75 – $150 average cost (standard 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
Tara Farmer
Fact-checked by
Kristen Cramer

Average cost to flush a tankless water heater

The cost to flush a tankless water heater is $150 to $350 for professional service or $100 to $300 for a DIY tankless flush kit. Costs vary based on your location, plumber rates, and the complexity of the tankless water heater unit. Regular flushing maximizes the unit's efficiency and lifespan.

Cost to flush a tankless water heater
Water heater type Average cost
Tankless water heater $150 – $350
Standard water heater $75 – $150
DIY tankless flushing $100 – $300

Get free estimates from water heater repair services near you.

Cost factors to flush a tankless water heater

Flushing a tankless water heater is a crucial maintenance task that helps remove sediment buildup and ensures optimal performance. The cost to flush a tankless water heater varies depending on several factors:

  • Labor cost: The primary cost factor is the labor charge by a professional plumber. Labor rates vary depending on the location, the plumber’s experience, and the complexity of the maintenance required.

  • DIY vs. professional plumber: Hiring a professional is more costly but ensures the flushing is done properly and any leaks or irregularities are addressed during the service.

  • Water heater complexity: More complex tankless units with advanced features like Wi-Fi connectivity, self-cleaning modes, or higher flow rates tend to be more difficult and time-consuming to flush properly.

  • Accessibility: If the tankless water heater is in a difficult-to-access area, the labor cost may increase due to the additional time and effort required.

  • Additional services: If the plumber includes any additional services beyond just flushing, such as inspecting other components, cleaning filters, or replacing parts, the cost will be higher.

  • Warranty requirements: Some manufacturers require the flushing to be done by approved or preferred plumbers to maintain the warranty, which may impact the cost.

  • Frequency: Manufacturers recommend flushing tankless water heaters at least once a year, but the frequency may vary depending on water quality and usage. More frequent flushing increases the overall maintenance cost.

DIY tankless water heater flush cost

The DIY cost to flush your own tankless water heater ranges from $100 to $300 for a tankless flush kit that includes all the supplies you need, including a submersible utility pump, hose connectors, a bucket with lid, two hoses, and descaling solution.

Cost to flush a tank water heater

A standard tank-style water heater flush costs $75 to $150. The plumber drains and flushes the tank to remove sediment buildup, refilling once the water runs clear. This comprehensive flushing technique eliminates harmful mineral deposits that can hamper the water heater's performance over time.

Tankless water heater maintenance

Tankless water heater maintenance costs $150 to $350 on average for a routine flush. Repair costs for a tankless water heater range from $300 to $1,300, but many repairs can be avoided by flushing and descaling the unit at least once per year.

Tankless water heater maintenance costs
Part or service Average cost
Tankless water heater flush $150 – $350
Fuse replacement $50 – $200
Pilot light replacement $100 – $300
Pipe replacement $200 – $500
Burner or heating element $400 – $800
Circuit board $400 – $800
Heat exchanger $600 – $1,300

A new tankless water heater installed by a professional plumber
A new tankless water heater installed by a professional plumber

FAQs about flushing a tankless water heater

How do you flush a tankless water heater?

Plumbers flush a tankless water heater by attaching hoses and then circulating a descaling or cleaning agent for the recommended time. After descaling, they flush again with clean water to remove any remaining residues. They finish the process by checking for leaks or irregularities in operation.

Why do you flush a tankless water heater?

You flush a tankless water heater to prevent mineral buildup that accumulates inside the tankless heater, especially in regions with hard water. The buildup eventually clogs pipes and reduces water flow, making it harder to heat the water.

How often should you flush a tankless water heater?

Get free estimates from water heater repair services near you.

Experts recommend flushing a tankless water heater annually in most areas. However, if you have hard water with high mineral content, consider flushing every 6 to 9 months to prolong the life of the tankless water heater.

Getting estimates from water heater repair services

Finding the right water heater repair service near you to flush your tankless water heater is easy if you follow these suggestions:

  • Look for plumbing services with good reviews on HomeGuide and Google.

  • Be prepared with the type and location of your water heater for a more accurate estimate.

  • Confirm they can complete any necessary repairs while they’re there.

  • Request a complete inspection to uncover potential issues.

  • Ask about the plumber's experience flushing water heaters specifically.

  • Consider off-season booking for better rates and availability.

Questions to ask a plumber about tankless water heater flushing

Ask a licensed plumber these important questions before scheduling a tankless water heater flushing service:

  • What type of descaling solution will you be using? Is it compatible with my water heater brand?

  • How long will the descaling solution circulate through the system?

  • What steps will you take to ensure all the cleaning solutions are flushed out?

  • Do you recommend replacing any filters or parts during the flushing process?

  • How long have you been flushing tankless water heaters?

  • Are you familiar with flushing my specific brand/model of water heater?

  • Do you have any certifications or training related to tankless water heater maintenance?

  • What is the estimated cost of flushing my tankless water heater?

  • Do you offer any discounts for bundling the flushing with other services?

  • Is there anything else you recommend checking or servicing while you're performing the flush?