Navien Tankless Water Heater Flush: DIY Guide

Maintaining your Navien tankless water heater ensures its longevity and efficiency, preventing hard water issues common in many homes. Scale buildup, a frequent problem, can be tackled with a simple DIY flush; consider using a flow restrictor to control the water flow during the process. Regular maintenance, like a navien tankless water heater flush, prevents costly repairs down the road. If you are in Sacramento, CA, knowing how to flush your Navien unit can save you money on plumber fees.

Keep Your Navien Tankless Water Heater Running Smoothly

A Navien tankless water heater is a significant investment, promising endless hot water and energy efficiency. To keep it running smoothly for years to come, regular maintenance is key. And a critical part of that maintenance is flushing the system.

Why Flushing Matters

Why is flushing so important? Over time, mineral deposits, commonly known as scale, can build up inside your tankless water heater. This buildup acts like cholesterol in your arteries, restricting flow and reducing efficiency.

The DIY Advantage

You might be thinking, "Do I really need to flush it myself?" The answer is, probably! While professional plumbers are certainly an option, tackling the flush yourself offers several advantages.

Cost Savings

First and foremost, you'll save money. Plumber fees can add up quickly. Doing it yourself only requires the cost of a few supplies.

Understanding Your System

Secondly, you'll gain a better understanding of how your system works. This knowledge can be invaluable for future maintenance and troubleshooting.

The Enemy: Scale Buildup

Scale buildup is the silent killer of tankless water heaters. It's caused by minerals like calcium and magnesium that are present in your water supply.

As water heats up, these minerals precipitate out of the solution and stick to the internal components of your water heater.

This scale acts as an insulator, reducing the heat transfer efficiency of your unit. This means your water heater has to work harder to heat the water, consuming more energy and increasing your utility bills.

Over time, scale buildup can also restrict water flow, leading to lower hot water pressure and potentially causing damage to the unit itself.

When to Call a Pro

While DIY flushing is generally straightforward, there are times when it's best to call a professional plumber.

If you're uncomfortable working with plumbing or electricity, don't hesitate to seek expert help. Safety should always be your top priority.

Additionally, if you encounter any serious problems during the flushing process, such as leaks or error codes that you can't resolve, it's best to consult a professional.

Understanding Why Flushing Matters: Scale Buildup and Water Hardness

So, we know flushing your Navien is important, but let's really dig into why. It all boils down to understanding how scale buildup forms and how it throws a wrench into your water heater's performance. This isn't just about cleaning; it's about proactively protecting your investment.

The Scale Effect: Robbing Your Tankless Water Heater

Scale buildup dramatically reduces the efficiency of your Navien tankless water heater.

Think of it as insulation – but not the good kind!

Scale forms a layer on the heat exchanger, which is the heart of your system.

This layer prevents the heat from efficiently transferring to the water.

As a result, the unit has to work harder and longer to heat water to the desired temperature.

This translates to increased energy consumption, which means higher utility bills. Over time, the constant strain can cause premature wear and tear on components, leading to costly repairs or even a complete system failure.

Water Hardness: The Culprit Behind Scale

The main driver of scale buildup is water hardness.

But what exactly is hard water?

Hard Water Defined

Hard water is water that contains a high concentration of minerals, primarily calcium and magnesium.

These minerals are naturally dissolved in water as it travels through soil and rock.

The higher the mineral content, the "harder" the water.

You might notice hard water through soap scum on shower doors, dry skin, or mineral deposits around faucets.

Soft Water vs. Hard Water: A Quick Comparison

Soft water, on the other hand, has a significantly lower mineral content.

It's often treated to remove calcium and magnesium ions, making it "softer."

While soft water might be gentler on your skin and plumbing, it can also be slightly more corrosive in some cases. Hard water is far more likely to cause scale buildup in your tankless water heater.

The Big Picture: Saving Money and Extending Lifespan

Regularly flushing your Navien tankless water heater is essential to prevent scale buildup, maintain optimal performance, and extend the life of your unit.

By removing mineral deposits before they become a major problem, you can significantly reduce the risk of costly repairs.

Think of it as preventative medicine for your water heater.

A little effort now can save you a lot of headaches (and money!) down the road.

Safety First: Protecting Yourself and Your Equipment

Before you even think about grabbing your tools and descaling solution, let's talk safety. Flushing your Navien tankless water heater is a manageable DIY project, but it involves gas, electricity, and potentially harsh chemicals. Taking the proper precautions isn't just recommended, it's essential for your well-being and the integrity of your equipment. This section will walk you through the necessary steps to ensure a safe and successful flushing experience.

The Foundation of Safety: Disconnecting Power and Gas

The absolute first step, before you touch anything else, is to completely disconnect both the gas and electrical supply to your Navien unit. This eliminates the risk of electric shock or gas leaks, both of which can have serious consequences.

Turning Off the Gas Supply

Locate the gas shut-off valve for your water heater. This is typically a valve on the gas line leading directly to the unit. Turn the valve to the "off" position. Double-check that the gas is completely shut off. You can test this by briefly turning on a hot water tap after you've shut off the gas. If no hot water flows after a minute or two, you've successfully cut off the gas supply.

Disconnecting the Power Supply

Next, turn off the circuit breaker that supplies power to your Navien tankless water heater. This is usually found in your home's electrical panel. Again, confirm that the power is off by checking the unit's display panel; it should be completely blank. Some units have a power switch on the unit itself which should also be switched off.

The Importance of Ventilation

Tankless water heaters, even when disconnected, can potentially retain small amounts of residual gas. To prevent any buildup of gas fumes, ensure adequate ventilation in the area around the unit. Open windows and doors to allow fresh air to circulate. This is especially crucial if you're working in a confined space.

Gearing Up: Personal Protective Equipment (PPE)

Think of PPE as your personal safety shield. It's a simple but effective way to minimize risks during the flushing process.

Protecting Your Eyes

Always wear safety glasses or goggles to protect your eyes from splashes of water or descaling solution. Even seemingly harmless liquids can cause irritation or, in some cases, more serious eye damage.

Protecting Your Hands

Wear chemical-resistant gloves to protect your hands from contact with descaling solutions and hot water. Some descaling solutions can irritate or even burn the skin. Gloves will also protect your hands from any grime or mineral deposits that may be present in the system.

Know Your Unit: Refer to the Manual

Your Navien tankless water heater's manual is your best friend during this process. It contains specific safety guidelines and instructions tailored to your particular model. Don't skip this step!

Manufacturer's Instructions First

Before you start any DIY work, take the time to carefully read and understand the manufacturer's instructions. Pay close attention to any specific warnings or precautions mentioned in the manual. This information can help you avoid potential hazards and ensure that you're following the correct procedures for your unit.

By taking these safety precautions seriously, you'll create a safer environment for yourself and protect your valuable equipment. Now that you've laid the groundwork for a safe flushing process, you can confidently move on to gathering your supplies and getting the job done right.

Gathering Your Supplies: The Right Tools for the Job

Alright, safety checks are done! Now, let's make sure you have everything you need before diving into the actual flushing process. Having the right tools and supplies not only makes the job easier, but also ensures a more effective and safer cleaning. Think of this as prepping your workstation – a little effort now saves a lot of headaches later.

Essential Tools and Equipment: Setting Up for Success

Here’s a detailed rundown of the essential tools you'll need.

Getting these beforehand will make the entire process much smoother.

Think of it like gathering ingredients before baking – you wouldn't want to start and realize you're missing something!

Isolation Valves: Controlling the Flow

Your Navien unit should already have isolation valves installed on both the cold water inlet and the hot water outlet. These are absolutely crucial.

They allow you to shut off the water supply to the unit without turning off the water to your entire house.

Make sure you know where these are and how they work before you begin. If your unit doesn't have isolation valves, seriously consider having them installed by a plumber for future maintenance.

Hoses: Connecting the Circuit

You'll need two hoses to create a closed-loop circulation system for the descaling solution. Standard washing machine hoses work perfectly for this. They're readily available at any hardware store and are designed to handle hot water.

Make sure they are long enough to reach from your water heater to the bucket containing the pump and solution. A length of 4-6 feet each is usually sufficient.

Submersible Pump: The Heart of the Circulation

A submersible pump is the key to circulating the descaling solution through your Navien unit. Choose a pump with a sufficient flow rate. A pump that can move at least 300-500 gallons per hour (GPH) should be adequate.

You don’t need anything industrial-strength here; a basic utility pump from your local hardware store will do the trick. Make sure it has fittings that are compatible with your hoses.

Bucket: Holding the Solution

You'll need a bucket to hold the descaling solution and house the submersible pump. A 5-gallon bucket is usually a good size.

Make sure it's clean and sturdy, and that it can comfortably accommodate the pump and the necessary amount of descaling solution.

Avoid using a bucket that has previously held chemicals, to prevent unwanted reactions.

Descaling Solution Options: Choosing the Right Cleaner

Now, let’s talk about the star of the show – the descaling solution. This is what's going to break down that stubborn scale buildup.

You have a few options here, each with its own pros and cons.

White Vinegar: The Natural Choice

White vinegar is a popular, cost-effective, and environmentally friendly option. It's a mild acid that's effective at dissolving mineral deposits.

It's generally safe for your unit and the environment, but it may take a bit longer to work than stronger chemical solutions.

CLR (Calcium, Lime, Rust Remover): The Heavy-Duty Option

CLR is a more potent chemical solution designed to dissolve calcium, lime, and rust. It's generally more effective than vinegar for heavy scale buildup.

However, it's also more harsh and should be handled with care. Always wear gloves and eye protection when using CLR, and make sure to rinse the system thoroughly after flushing.

Commercial Descaling Solutions: The Professional Touch

There are also several commercial descaling solutions specifically formulated for tankless water heaters. These are often a blend of different acids and detergents designed to safely and effectively remove scale buildup.

They can be more expensive than vinegar or CLR, but they may be worth the investment if you want a solution that's specifically designed for your unit. Follow the manufacturer's instructions carefully when using these products.

Dilution Ratios: Getting the Mix Right

Regardless of which descaling solution you choose, it's important to dilute it properly. Using a solution that's too concentrated can damage your unit, while a solution that's too weak may not be effective.

• White Vinegar: Use undiluted or a 50/50 mix with water for milder cases.
• CLR: Typically, a 1:6 ratio with water is recommended, but always check the product label for specific instructions.
• Commercial Descalers: Follow the manufacturer's dilution guidelines precisely.

Miscellaneous Items: The Finishing Touches

Don't forget these often-overlooked items that can make the process much easier and cleaner.

• Wrenches: For tightening hose connections (adjustable wrenches are the most versatile).
• Screwdrivers: For removing access panels or cleaning the filter screen.
• Rags: For cleaning up any spills or drips. Have plenty on hand!

With all your supplies gathered, you're now fully equipped and ready to tackle the flushing process. Take a deep breath, double-check your gear, and let's get started!

Step-by-Step Guide: Flushing Your Navien Tankless Water Heater

Alright, here's where we get our hands dirty! Flushing your Navien tankless water heater might seem daunting, but with these step-by-step instructions, you'll be a pro in no time. Remember to stay safe and take your time – rushing can lead to mistakes.

Let's break it down into manageable steps.

Prep Work: Setting the Stage for a Successful Flush

Before you even think about touching any hoses, safety is paramount.

Turning Off the Gas and Power

First and foremost, turn off the gas supply to your Navien unit. This is usually done via a valve on the gas line leading to the heater. Make sure it's completely shut off.

Next, disconnect the power supply to the unit. Locate the breaker switch in your electrical panel that corresponds to the water heater and flip it to the "off" position.

This ensures there's no risk of gas leaks or electrical shocks during the flushing process.

Closing the Isolation Valves

Now, close the isolation valves on both the cold water inlet and the hot water outlet lines. These valves are designed to shut off the water supply directly to the unit, allowing you to work without turning off water to the entire house.

Turn the handles until they are fully closed. This will prevent any water from flowing into or out of the unit during the cleaning process.

Setting Up the System: Creating the Circulation Loop

With the unit safely isolated, we can now set up the circulation system for the descaling solution.

Connecting the Hoses

Connect one end of a washing machine hose to the cold water isolation valve outlet and the other end to the bottom of your bucket. Then connect one end of the other washing machine hose to the hot water isolation valve outlet and place the other end into the same bucket. These hoses will create a closed loop for the descaling solution to circulate.

Make sure the connections are snug and secure to prevent leaks.

Positioning the Submersible Pump

Place the submersible pump inside the bucket. Ensure the pump is fully submerged and its output is directed to the hose going into the hot water isolation valve. This will ensure that the descaling solution will flow through the Navien unit.

The pump is the heart of our cleaning system, so proper placement is key.

Mixing the Descaling Solution: Getting the Chemistry Right

The descaling solution is what will actually dissolve the mineral buildup inside your Navien unit. Using the correct dilution ratio is crucial to avoid damaging the heater.

Dilution is Key

Refer back to the "Descaling Solution Options" section and carefully follow the recommended dilution ratio for your chosen solution. Whether you're using white vinegar, CLR, or a commercial descaler, always mix it with water according to the manufacturer's instructions.

A common ratio for CLR is 1:6 (CLR to water), while white vinegar can often be used undiluted or in a 50/50 mix with water. Commercial descalers will have specific instructions on the label.

Circulating the Solution: Let the Cleaning Begin!

Now for the exciting part – circulating the descaling solution through your Navien unit!

Turning On the Pump

Plug in the submersible pump and switch it on. You should see the descaling solution circulating through the hoses and into the water heater. Let the pump run for the recommended time, typically 1-2 hours.

During this time, the descaling solution will work its magic, dissolving the mineral deposits and scale buildup inside the unit.

Monitoring the Process

Keep an eye on the system during the circulation process. Check for any leaks or unusual noises. If you notice anything concerning, stop the pump immediately and address the issue before continuing.

It's a good idea to periodically check the solution in the bucket as well. If it becomes excessively dirty or cloudy, you may need to drain and replace it with a fresh batch.

Draining and Rinsing: Flushing Out the Impurities

After the circulation period, it's time to drain the used descaling solution and thoroughly rinse the system with clean water.

Proper Disposal

Turn off and unplug the submersible pump.

Carefully disconnect one of the hoses from the isolation valve (preferably the one connected to the pump's output). Direct the hose into a drain (a utility sink or floor drain works well) and allow the used descaling solution to drain out of the system.

Dispose of the used solution responsibly. Check local regulations for proper disposal methods, especially if you used a chemical descaler like CLR.

Flushing with Clean Water

Once the system is drained, reconnect the hoses to the isolation valves. Now, open the cold water isolation valve slightly to allow fresh water to flow through the system.

Let the water run until it comes out clear and free of any descaling solution residue. This may take several minutes, so be patient.

Repeat this process several times to ensure all traces of the descaling solution are removed.

Cleaning the Filter Screen: A Final Touch

As a final step, it's a good idea to clean the filter screen on your Navien unit.

Accessing and Cleaning

Refer to your Navien owner's manual for instructions on how to access the filter screen. It's usually located on the cold water inlet side of the unit.

Carefully remove the filter screen and inspect it for any debris or buildup. Rinse it thoroughly with clean water to remove any particles.

Once the filter screen is clean, reinsert it into its housing and ensure it's properly secured.

With that, you've successfully flushed your Navien tankless water heater! You're one step closer to a more efficient and longer-lasting system.

Reassembly and Start-Up: Getting Back to Hot Water

Alright, you've flushed your Navien like a champ. Now it's time to get that hot water flowing again! This part is all about carefully putting everything back together and making sure your system is running smoothly. Don't rush this step; a little attention to detail now can save you headaches later.

Reconnecting Everything: A Careful Approach

Think of this as the reverse of taking it apart. Precision is key, so let's walk through it.

Ensuring a Leak-Proof Seal

Before you get too excited, make sure both isolation valves are fully closed. This will prevent any sudden gushes of water when you reconnect the lines.

Now, carefully reconnect the hoses to the isolation valves. Tighten the connections securely, but don't overtighten them! You don't want to damage the threads.

Once everything's connected, take a moment to visually inspect all the connections. Look for any signs of misalignment or potential leaks.

This is your chance to catch a problem before it becomes a bigger issue.

Turning the System Back On: A Gradual Return

Now for the moment of truth – bringing your Navien back to life. But remember, slow and steady wins the race.

Restoring Gas and Power

First, slowly turn the gas back on. Listen carefully for any hissing sounds, which could indicate a leak. If you smell gas, immediately turn off the gas supply and call a qualified professional.

Next, head back to your electrical panel and flip the breaker switch for the water heater back to the "on" position.

Priming the Pump (If Applicable)

Some Navien models might require you to prime the pump after being shut down. Refer to your owner's manual for specific instructions on how to do this. Skipping this step could prevent your unit from firing up properly.

Testing: The Proof is in the Hot Water

The final stage – verifying that your efforts were successful!

Checking Flow and Temperature

Open a hot water faucet in your home and let the water run. It may take a few minutes for the hot water to reach the faucet as the system purges any remaining air.

Check the water flow rate. Is it consistent and strong, like before? Also, check the water temperature. Is it reaching your desired setting?

Listening for Unusual Noises

Pay close attention to the sounds coming from your Navien unit. Are there any unusual noises, like banging, gurgling, or excessive humming? These could indicate air in the lines, a pump issue, or other problems. If you hear anything concerning, consult your owner's manual or a qualified technician.

If everything checks out – consistent flow, desired temperature, and no weird noises – congratulations! You've successfully reassembled and started up your Navien tankless water heater.

Enjoy that hot shower!

Troubleshooting: Common Issues and Solutions

So, you've flushed your Navien, but something's not quite right? Don't panic! It's common to encounter a few hiccups along the way. Let's troubleshoot some of the most frequent issues that pop up after flushing and how to tackle them.

Leaks: A Drop Here, A Drop There...

Leaks are probably the most common post-flush problem. They usually occur around the connections you worked with during the process.

Identifying the Source

The first step is to pinpoint the exact location of the leak. Grab a flashlight and carefully inspect all the connections you disconnected and reconnected during the flush.

Look closely at the hose connections to the isolation valves, the pressure relief valve, and any other fittings you may have disturbed.

Tightening Connections: A Gentle Approach

Often, a simple tightening of the connection is all it takes. Use a wrench to gently tighten the fitting, but be careful not to overtighten! You could damage the threads or the fitting itself. A quarter turn might be all you need.

Replacing Washers: When Tightening Isn't Enough

If tightening doesn't stop the leak, the washer inside the connection might be worn or damaged. Replacing the washer is a simple and inexpensive fix.

Turn off the water supply to the unit before disconnecting the fitting to replace the washer. Make sure you use the correct size and type of washer for the connection.

Pipe Joint Compound: For Stubborn Leaks

For persistent leaks that just won't quit, even after tightening and replacing the washer, consider using a pipe joint compound (also known as Teflon tape or pipe dope) on the threads of the fitting.

Follow the manufacturer's instructions for applying the compound, and be sure to clean up any excess.

Error Codes: Deciphering the Digital Language

Navien units are equipped with sophisticated diagnostic systems that display error codes when something's amiss. These codes can seem cryptic, but they're actually valuable clues to the problem.

Consulting the Manual: Your First Stop

Your Navien owner's manual is your best friend when it comes to error codes. It will list all the possible codes and their corresponding meanings.

Locate the error code displayed on your unit and find it in the manual. The manual will usually provide troubleshooting steps to resolve the issue.

Common Error Codes and Solutions

Some common error codes relate to:

• Ignition Failure: Could indicate a gas supply issue or a problem with the igniter.

• Overheating: Might be caused by scale buildup (ironically!), a faulty temperature sensor, or insufficient water flow.

• Flow Sensor Issues: Suggests a problem with the flow sensor, which monitors water flow through the unit.

• Air Pressure Switch: Could be a venting problem.

Resetting the Unit: A Simple First Step

Sometimes, simply resetting the unit can clear an error code. Turn off the power to the unit at the breaker for a few minutes, then turn it back on. See if the error code reappears.

Unusual Noises: When Your Water Heater Sings a Strange Tune

A healthy Navien should operate relatively quietly. Unusual noises, like banging, gurgling, or excessive humming, can indicate a problem.

Air in the Lines: The Gurgling Culprit

Gurgling sounds often indicate air trapped in the lines. This can happen after flushing. Try running hot water from all your faucets for a few minutes to purge any trapped air.

Pump Issues: The Humming Suspect

Excessive humming could point to a problem with the circulation pump. Check the pump for any obstructions or debris. Refer to your owner's manual for instructions on cleaning or servicing the pump.

Scale Buildup: The Banging Bandit

Banging or knocking sounds can sometimes be caused by scale buildup, even after flushing. It might mean you need to repeat the flushing process, perhaps with a stronger descaling solution.

When to Call a Pro: Knowing Your Limits

While DIY flushing can save you money, it's essential to know when to call a qualified plumber.

• If you're uncomfortable with any step of the process: Don't hesitate to seek professional help. It's better to be safe than sorry.
• If you encounter serious problems that you can't resolve: If you've tried troubleshooting and the issue persists, it's time to call in the experts. Don't risk further damage to your unit by attempting repairs beyond your skill level.
• If you smell gas: This is a serious safety hazard. Immediately turn off the gas supply and call your gas company or a qualified plumber.
• If you're dealing with complex error codes or internal component failures: These issues often require specialized knowledge and tools to diagnose and repair.

Remember, your Navien tankless water heater is a valuable appliance. Taking care of it properly will ensure years of reliable hot water. When in doubt, don't hesitate to consult a professional!

Maintaining Your Tankless Water Heater: A Long-Term Investment

Congratulations, you've successfully flushed your Navien tankless water heater! But the journey to hot water bliss doesn't end there. Think of flushing as just one step in a larger commitment to keeping your unit running smoothly for years to come. Regular maintenance is key to protecting your investment and ensuring a consistent supply of hot water when you need it most. Let's explore why ongoing care is so important.

The Importance of Regular Maintenance

Think of your tankless water heater like a car. You wouldn't just drive it until it breaks down, right? You'd change the oil, rotate the tires, and perform other routine maintenance to keep it running in top condition. The same principle applies to your Navien. Neglecting maintenance can lead to decreased efficiency, costly repairs, and a significantly shortened lifespan.

Regular maintenance is not just about fixing problems; it's about preventing them in the first place.

Establishing a Flushing Schedule: Know Your Water

One of the most important aspects of maintenance is establishing a regular flushing schedule. The frequency of flushing depends largely on the hardness of your water.

Understanding Water Hardness

Water hardness refers to the amount of dissolved minerals, primarily calcium and magnesium, in your water. The higher the mineral content, the harder the water. Hard water accelerates scale buildup inside your tankless water heater.

Recommended Flushing Frequency

Here's a general guideline for flushing frequency based on water hardness:

• Soft Water (less than 3 grains per gallon): Flush every 2-3 years.
• Moderately Hard Water (3-7 grains per gallon): Flush every year.
• Hard Water (7-10 grains per gallon): Flush every 6-12 months.
• Very Hard Water (over 10 grains per gallon): Flush every 3-6 months.

It's recommended to get your water tested to determine its hardness. You can purchase a water hardness testing kit online or at your local hardware store. Also, consider checking with your local water municipality for an average hardness level.

Remember, this is just a guideline. If you notice a decrease in hot water flow or increased energy bills, it might be time to flush, even if it's sooner than recommended.

Benefits of Preventative Maintenance

Investing in regular maintenance for your tankless water heater offers numerous benefits.

Improved Water Heater Efficiency

Scale buildup acts as an insulator, making it harder for your unit to heat water. This forces your water heater to work harder, consuming more energy. Regular flushing removes scale, restoring your unit's efficiency and lowering your energy bills.

Extended Lifespan of the Unit

By preventing scale buildup and other issues, you can significantly extend the lifespan of your Navien tankless water heater. Regular maintenance helps to protect the unit's components from damage, ensuring years of reliable performance.

Reduced Risk of Costly Repairs

Preventative maintenance can help you avoid costly repairs down the road. Addressing minor issues early on can prevent them from escalating into major problems that require professional attention.

Think of regular maintenance as an investment in the long-term health and performance of your tankless water heater. It's a small price to pay for peace of mind and years of hot water enjoyment.

So, there you have it! Giving your Navien tankless water heater a flush might seem daunting at first, but with a little preparation and these simple steps, you can keep it running smoothly for years to come. Happy flushing!