How Much Does Tankless Water Heater Maintenance Cost?

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If you want to own your tankless water heater for as long as possible, regular maintenance, servicing, and occasional repair work are all essential.

Here, we’ve outlined the typical costs of tankless water heater repair and maintenance, discussed the factors that affect these costs, and looked at how you can reduce these costs where possible.

📌 Key Takeaways:

  • The average cost of tankless water heater maintenance is $40 to $1,100.
  • Factors affecting the cost of tankless water heater repair, servicing, or maintenance include the scope of the job, the materials required, the water heater size and brand, the time required for the job, and your location.
  • You might be able to reduce maintenance and repair costs by doing the job yourself (when possible), asking around for quotes, buying your own parts and materials, or buying a new tankless water heater.

💸 What’s The Average Cost Of Tankless Water Heater Maintenance?

On average, tankless water heater maintenance costs $40 to $1,100, possibly even higher.

There’s a big disparity between maintenance costs because there are so many different jobs that your tankless water heater might require, with different complexities and different material costs.

Getting your tankless water heater serviced will likely only cost you for the plumber’s labor hours, while typical repair costs are usually higher due to the added expense of the materials and components required.

📋 6 Factors That Affect The Cost Of Tankless Water Heater Maintenance

Before we look at the cost of specific tankless water heater repairs, maintenance, and servicing jobs, let’s consider the factors that affect the general cost of tankless water heater maintenance cost.

1) Scope Of The Job

First, the scope of the job will likely affect the cost of maintenance for your tankless water heater.

Generally, the bigger the job, the longer it’ll take, the more tools and materials will be required, and the more expensive it’ll be.

Technician checking on water heater damage

2) Materials Required

The type and number of materials required will also affect tankless water heater maintenance costs.

If the maintenance or repair job requires unique materials or expensive parts, this cost will be added to the overall bill.

On the other end, if your plumber is carrying out a routine maintenance or repair task that uses tools and materials they already have to hand, the average cost of the job will likely be lower.

3) Water Heater Size

Maintenance or repair costs for a tankless water heater may be affected by the size of the heater unit.

The bigger the heater, the bigger its components. That might mean you have to pay more for parts to repair the heater, and certain maintenance jobs (like flushing) may cost more because they’ll take longer and require more materials.

4) Time Required

The time required for a tankless water heater maintenance or repair job affects how much your plumber will charge for their manual labor.

Most plumbers quote a flat fee upfront for a certain job based on the materials required and their labor costs for the time it should take. Others charge per hour alongside the additional material/supply costs.

The bigger the job and the more time it’ll take to carry out, the more your plumbing contractor will charge.

Water heater repair

5) The Tankless Water Heater Brand

There are numerous different tankless water heater manufacturers, and different products by different brands often have different maintenance costs.

Some heaters are more affordable to maintain because their parts are more easily accessible and are low-cost to repair. Maintenance and repair costs for other heaters are higher because they have more complex designs or more expensive components.

6) Your Location

Finally, your location will play a part in how much you spend on tankless water heater maintenance.

Certain states have a higher cost of living, meaning that the cost of services is higher. If you live in a city, you’re likely to pay more for water heater repairs and servicing than you would if you live in a suburban location.

🧰 Average Cost Of Different Tankless Water Heater Maintenance Jobs

Below, we’ve broken down the average cost of maintenance or servicing jobs for a tankless water heater:

Maintenance JobAverage Cost Range
Flushing The System$150-$250
Cleaning The Air Filter$45-$150

Flushing The System

On average, plumbers charge $150-$250 to flush a tankless hot water heater.

This job usually takes 1-2 hours and involves connecting the heater to a pump and sending a cleaning or descaling solution through the unit, removing mineral deposits and sediment. The cost of tankless water heater flushing takes into account the plumber’s manual labor costs and the cost of the equipment and materials used.

Flushing the cleaner

Cleaning The Air Filter & Replacing The Water Filter

The average of cleaning your heater’s air filter and replacing the water filter (if it has one) is $45-$150, depending on your plumber’s hourly rate.

Since these are small jobs (cleaning an air filter takes just minutes), your plumber is unlikely to offer these services on their own. They’ll usually add them to a bigger regular maintenance task, like flushing the heater, so they don’t have to make the trip to your home for a five-minute job.

🔧 Average Cost Of Different Tankless Water Heater Repair Jobs

Here’s a breakdown of the most common water heater repair jobs, and how much they cost:

Repair JobAverage Cost Range
Broken Thermostat$100-$300
Pilot Light Problem$65-$400
Leaking Heater Or Pipes$50-$1,000
Tripped Breaker/Blown Fuse$20
Pressure Relief Valve$75-150
Cracked, Leaking, Or Corroded Pipes$120-$300
Low Pressure Problems$75-$500
Unusual Rumbling Noise$50-$550
Frozen Pipes$200-$450
Rust Problems$200-$800
Rotten Egg Water Smell$150-$400
Cold Water Sandwich $300-$900

Fixing A Broken Thermostat

The cost of fixing a broken thermostat is about $100-$300 when you hire a professional plumber.

It’s possible to DIY replace broken thermostats, which can help you save money. Just make sure to follow the instructions carefully in your user manual (if this information is available – otherwise look online). You should also make sure to switch off the breaker before getting started.

Remedying A Pilot Light Problem

If your tankless water heater uses gas, it should have a pilot light that might, for several reasons, go out. The average cost of fixing a pilot light issue in your water heater is $65-$400.

The cost of remedying a pilot light issue is determined by the plumber’s hourly costs, how long it takes to resolve the issue, and the cost of a replacement part (if needed).

Again, you can fix this issue yourself, but we don’t recommend doing so. It’s much safer to hire a licensed plumber with experience in working with gas heaters.

Repairing Leaking Heater Or Pipes

Leaks from your tankless water heater or the connecting pipes have the potential to be very expensive, depending on the severity of the leak. Most leaks cost around $50-$375 to repair, depending on the cause of the leak and how much work needs to go into the repair job.

Aside from the cost of actually fixing or stopping the leak, you may have to repair damage to your home caused by the leak, which could cost upwards of $1,000. We don’t recommend attempting to fix a leak yourself – leave this one to a professional.

Leaking water heater

Replacing A Tripped Breaker/Blown Fuse

Fixing blown fuses and tripped breakers are common tankless water heater repair jobs. The cost of these straightforward repairs is around $20.

The cost depends on what you need fixing. If your blown fuse needs to be replaced, you’ll have to pay for this new component. Replacing a blown fuse is a really easy task, so you don’t need to hire a plumber and pay extra for their labor costs.

Repairing A Pressure Relief Valve

If your tankless water heater’s pressure relief valve breaks, you can expect to pay around $75-150 for repairs.

It’s essential that you get your pressure relief valve fixed as soon as possible, since it plays the essential role of relieving pressure inside the heater as it heats and expands.

The exact cost of this job depends on whether the pressure relief valve can be repaired or whether a complete replacement is needed. We don’t recommend attempting this job yourself due to the importance of the valve.

Fixing Cracked, Leaking, Or Corroded Pipes

Noticed leaking, cracked, or corroded pipes leading to or from your water heater? You’ll need to hire a plumber for pipe repair, with an average cost of $120-$300.

This cost depends on factors including how much of your plumbing system must be repaired or replaced, the accessibility of the location, and more. A partial pipe replacement will be cheaper than a complete replacement.

Again, hire a plumber for this job. Don’t try to fix broken pipes yourself – you might not remedy the issue completely, leading to expensive damage later.

Checking main water pipe in home

Remedying Low Pressure Problems

The cost of fixing low pressure problems in tankless water heaters is $75-$500 on average.

Usually, an issue with low pressure in a tankless heater is caused by problems with the pressure regulator or valves. If these only need to be adjusted, the repair cost will be low.

Low pressure in a tankless water heater might also be caused by a buildup of sediment in the heater pipes, which can be remedied by flushing the heater.

Troubleshooting & Fixing Unusual Rumbling Noise

There are a few causes of unusual rumbling in a tankless water heater, including sediment buildup, damaged pipes, or an issue with the heating element.

The average cost to fix a heater that’s emitting unusual rumbling noises is $50-$550. The cost depends on the complexity of the repair work that’s required, and which (if any) components need to be replaced.

Repairing Frozen Pipes

The average cost to repair frozen pipes in tankless water heaters is $200-$450.

The cost will include the time it takes for your plumber to thaw the frozen pipe sections, and possibly the cost of insulation to prevent the pipes from freezing in the future.

Fixing Rust Problems

Assuming that your rusty tankless hot water heater can be repaired, you’re looking at an average cost of $200-$800 for the job. This will involve cleaning or replacing rusty, corroded sections of pipe in and around the heater unit.

If you allow rust to accumulate over a long period, your heater may be beyond repair, and you’ll have no choice but to replace it with a new one. That’s a more expensive outcome – new tankless water heaters cost $800 to $3,500 on average.

Rusted water heater anode

Remedying A Rotten Egg Water Smell

If your hot water smells like rotten eggs, you probably have bacteria buildup in your tankless hot water heater. The cost to remedy this issue, usually by flushing and cleaning the heater, is around $150-$400.

If your hot and cold water smell like rotten eggs, the problem likely isn’t with your heater, but with your water supply itself (especially if your water comes from a groundwater well).

Fixing “Cold Water Sandwich”

Finally, a case of “cold water sandwich” – where your hot water temperature randomly drops for a few seconds, then goes back to hot – is around $300-$900 to fix, depending on the solution that your plumber deems is best for this issue.

Commonly, a plumber will recommend installing a mini tank water heater for a specific fixture (usually your shower), and the cost of purchasing and installing the heater depends on its size and the project scope.

🔂 Cost To Replace Tankless Water Heater Components

Let’s look at some of the tankless water heater components that commonly need replacing, and their average replacement costs:

Component ReplacementAverage Cost Range
Pressure Relief Valves $20-$60
Heating Elements $25-35
Gas Valve$60-$175

Pressure Relief Valves

The cost of a replacement pressure relief valve for your tankless unit is $20-$60. Remember, this is just the cost of the valve itself – and we recommend getting the valve professionally replaced by a plumber, which will bring up your total spend.

Heating Elements

A single heating element for a tankless water heater costs as little as $25-35. Again, we don’t recommend replacing the heating element yourself, so you’ll also need to factor in the cost of a plumber.

Gas Valve

Most gas valves have a 15-year life expectancy, and an old or faulty valve costs around $60-$175, depending on the valve’s design. You should hire a plumber to replace the valve, with an average total cost of $350.

🆚 DIY Tankless Water Heater Maintenance Cost vs Professional Plumber Costs

As you can see from the above lists, there are a few tankless water heater maintenance and repair jobs that you can carry out yourself.

To recap, these jobs include:

  • Flushing the water heater to remove scale and sediment buildup
  • Cleaning the heater’s air filter and replacing the water filter
  • Fixing a broken thermostat
  • Replacing a blown fuse

The cost of DIY maintenance, servicing, or repairs for your tankless water heater is lower because there’s no labor cost included when you’re doing the work yourself.

Most plumbers charge $50-$250 per hour, depending on their skill level and the complexity of the job required.

So, not only are you paying for the materials and parts required for the job, but you’re also paying the plumber’s hourly wages.

Our advice is to only consider doing your own work when the task at hand is simple and won’t result in a catastrophe if you accidentally do something wrong. Follow online tutorials or the instructions in your user manual carefully, and don’t make any major changes that you’re not sure about.

Professional tankless water heater repair

📉 How To Reduce Tankless Water Heater Maintenance Cost

Many tankless water heater repairs and maintenance jobs are unavoidable. However, while you shouldn’t simply put off the jobs themselves, there are at least a few ways that you can save money on these tasks.

DIY (When Possible)

As we mentioned above, you can take on a lot of the tankless water heater repair and maintenance tasks yourself, saving the extra expense of a plumber’s manual labor costs.

If you’re a confident DIY-er and you can follow instructions, it’s worth considering doing the repairs and servicing jobs that are safe for unlicensed homeowners to carry out.

Ask Several Plumbers For Quotes

Another way to save money on tankless water heater repair or maintenance is to ask around for several quotes and settle on the contractor who offers the best value for money.

Never settle with the first quote you receive. You might end up paying above average for your local area, with no way to know because you haven’t shopped around. Worse, a small percentage of tradesmen take advantage of customers that they deem to be knowledgeable about their services, and may try to charge extortionate high for a relatively quick and simple job. You’re less likely to fall foul to this if you get multiple quotes from multiple plumbers.

Buy Your Own Parts And Materials

Buying your own parts and materials will also help you to save money on professional tankless water heater repair and maintenance.

A plumber will usually have access to affordable parts and materials for water heaters, but that doesn’t mean they’ll quote you accurately. Our advice is to wait until the plumber has produced a quote for your job, then check the price of the materials needed and see if you can get the same quality materials for cheaper. If there’s a big price jump between what you’re seeing and what the plumber is quoting, ask them to knock the cost of materials off their quote and buy them yourself.

Water heater replacement parts

Consider Replacing Your Water Heater

A tankless water heater is a bit like a car in the sense that towards the end of its lifespan, it becomes a money pit, and paying hundreds or thousands on repair costs simply isn’t worth it when the unit itself will probably only last a couple more years.

While replacing your water heater may seem counterintuitive, it’ll help you save money on maintenance and repairs in the long run. Imagine you spend $2,000 over five years to keep your old, faulty water heater alive. You may as well buy a new one for a similar cost and pay only for regular servicing for the next 10+ years.

The average lifespan of a tankless water heater is 15-20 years. If you’re unsure whether it’d be better to replace your heater, ask your local plumber to inspect it and give you their verdict.

✅ Additional Considerations To Make

There are a few additional considerations you should make when determining the cost of tankless water heater repair or maintenance.

These include:

  • The heater warranty. Most tankless water heaters have warranties that enable you to get certain repairs or replacement parts for the heater at a free or discounted cost. This is something to look into if your heater is still relatively new and may still be within the warranty period.
  • The heater lifespan. When deciding whether to repair or replace your tankless hot water heater, consider the age of the heater. If your heater is 10-15 years or older, it probably makes more sense to replace it with a new one.
  • What to do with your old heater. If you do decide to replace your tankless heater, you’ll need to have an action plan for your old water heater. Your plumber should offer a removal and disposal service for water heaters, usually costing $60-$130 on average.
  • Permits for certain jobs. Depending on where you live, you might need to obtain a permit for certain tankless hot water heater enhancements or repairs. Permits sometimes come at a cost, so be sure to discuss this with your plumber if you’re concerned.

📑 Final Word

Hopefully, this guide has covered everything you wanted to know about the cost of maintaining and repairing tankless water heaters.

If you have any additional questions, check our FAQs below – there’s a good chance we’ve answered them there.

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❔ FAQs

Do tankless water heaters need regular maintenance?

Yes, tankless water heaters need regular maintenance to enable them to perform efficiently throughout their lifespans and prevent problems that could lead to early failure, like sediment buildup and scale formation. The biggest maintenance job is flushing the heater. Aside from that, you’ll just need to clean the air filter and replace the water filter (if your heater has one).

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

The average cost to flush a tankless heater is $150-$250. Aim to flush your heater twice a year to maintain optimum performance.

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

Rinnai tankless water heaters cost around $45-$200 for general maintenance and servicing, while repair work costs $375 on average. It’s difficult to give an accurate price estimate for repair costs because they depend on the scope of the job and the cost of the component that needs to be fixed or replaced.

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

The average cost of servicing a Navien tankless water heater is $45-$200, and the repair average cost for this brand of water heater is $200-$700.

What is the labor cost to replace a tankless water heater?

The labor cost to replace a tankless water heater is around $120-$480 for 2-3 hours of work, depending on the scope of the project and your plumber’s hourly rate. Your location, the scope of the project, and the brand of the heater will all affect your plumber’s labor costs.

What is the life expectancy of a tankless water heater?

The average life expectancy of a tankless water heater is 15 to 20 years, assuming that you properly maintain the heater, make timely repairs whenever necessary, and service the heater as outlined int he user manual.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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