E513 Navien Tankless Water Heater: Your Complete DIY Troubleshooting

ByDavid Clark

There’s nothing quite like the jolt of an unexpectedly cold shower to ruin your morning. You check your Navien tankless water heater, and instead of reassuring green light, you see a cryptic error code: E513. It’s a frustrating moment we see all the time, but don’t worry—we’re here to walk you through it.

As HVACR professionals, we can tell you that an e513 navien tankless water heater error is one of the more common issues homeowners face. It’s a safety alert, and while that sounds serious, the cause is often something a confident DIYer can safely inspect and even resolve with the right guidance.

Imagine getting your hot water back in under an hour without a costly service call. Picture having the confidence to maintain your high-efficiency unit, ensuring it runs smoothly for years to come.

In this complete e513 navien tankless water heater guide, we’ll demystify this error code, provide safe, step-by-step troubleshooting instructions, and help you understand exactly when it’s time to call in a certified technician. Let’s get that hot water flowing again.

What Exactly Is the E513 Error on a Navien Tankless Water Heater?

First things first, let’s translate that code. An E513 error on a Navien unit signals a “flame loss” condition. In simple terms, your water heater tried to fire up, but its main safety sensor couldn’t confirm that a stable flame was present and burning correctly.

Think of it as a diligent safety manager. The control board tells the gas valve to open and the igniter to spark. A flame is created, but if the flame sensor (also called a flame rod) doesn’t send back a strong “all clear” signal within a few seconds, the board immediately shuts off the gas supply. This prevents raw, unburned gas from filling your unit or home, which is a critical safety feature.

The Most Common Culprits Behind a Flame Loss Error

While it could be a major component, the E513 error is most frequently caused by a few simple, fixable issues. Here’s what’s likely happening inside your unit:

  • A Dirty Flame Sensor: This is the number one cause. Over time, a thin layer of carbon or oxidation builds up on the flame rod, acting as an insulator. The sensor can’t “feel” the flame, even if it’s burning perfectly.
  • Ignition System Problems: A weak or failing igniter, or an improper gap between the igniter and the burner, can result in a poor or delayed flame that the sensor can’t detect in time.
  • Gas Supply or Pressure Issues: If the gas pressure is too low or inconsistent, the flame will be weak and unstable, triggering the safety shutdown.
  • Blocked Vents or Condensate Line: Tankless water heaters need precise airflow. A bird’s nest in the exhaust pipe or a clogged condensate drain can throw off the air-to-fuel ratio and extinguish the flame.

Safety First: Before You Begin Troubleshooting

Before you open the cover of your water heater, we need to take a moment for safety. We are working with gas and electricity. These steps are non-negotiable and are the foundation of all e513 navien tankless water heater best practices.

Don’t worry—these are straightforward checks, but they are absolutely essential for your safety. We’ll go through them together.

Gather Your Tools

You won’t need a full workshop for this. Most of the work can be done with a few basic items:

  • A Phillips head screwdriver (for the cover and components).
  • A small nut driver or socket set (often 1/4″ or 5/16″).
  • A clean, dry cloth or paper towels.
  • A piece of very fine steel wool (grade #0000) or a crisp, new dollar bill. (Yes, really! We’ll explain why.)
  • A flashlight or headlamp for better visibility.

Power Down and Secure the Unit

This is the most critical step. You must completely cut power and gas to the unit before proceeding.

  1. Turn Off Electrical Power: Go to your home’s main electrical panel and flip the circuit breaker that controls your tankless water heater to the OFF position. Don’t just unplug it; the breaker ensures no stray voltage.
  2. Shut Off the Gas Supply: Locate the gas valve on the pipe leading to your water heater. It usually has a red or yellow handle. Turn the handle a quarter-turn so it is perpendicular (at a 90-degree angle) to the pipe. This stops the flow of gas.
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Once you’ve done this, you’re ready to safely open the unit and investigate.

How to Fix the E513 Navien Tankless Water Heater Error: A Step-by-Step Guide

With the unit powered down and the gas off, we can now work through the most common solutions. Follow these steps in order, as they go from simplest to most involved. This is your core how to e513 navien tankless water heater action plan.

Step 1: The Simple Reset (Just in Case)

Before disassembling anything, let’s rule out a simple glitch. If you haven’t already, restore power at the breaker and turn the gas back on. Power the unit on and see if the error clears. If it fires up normally, it may have been a one-time fluke. If the E513 error returns, proceed with shutting everything down again and move to the next step.

Step 2: Inspect Vents and Condensate Drain

Your heater needs to breathe. Let’s make sure it can.

  • Check Intake and Exhaust Vents: Go outside and look at where your PVC vent pipes terminate. Check for obstructions like leaves, bird nests, snow, or insect hives. Clear away anything blocking the openings.
  • Inspect the Condensate Trap: High-efficiency units like Navien produce condensation. Find the small plastic trap connected to a drain line at the bottom of the unit. If it’s full of water or gunk, it can cause pressure issues. Carefully remove it, clean it with soap and water, and reinstall it.

Step 3: The Main Event—Clean the Flame Sensor

This is the most common fix and a cornerstone of our e513 navien tankless water heater tips. The flame sensor is a thin metal rod with a white ceramic insulator at its base, positioned directly in the path of the flame.

  1. Locate and Remove the Sensor: With the front cover off, look for the burner assembly. The flame sensor is typically held in place by a single screw. Carefully remove the screw and gently pull the sensor straight out. Be mindful of the wire connected to it.
  2. Inspect the Rod: Look closely at the metal rod. Does it have a dull, white, or black coating on it? That’s the carbon buildup we need to remove.
  3. Clean It Gently: Take your very fine steel wool or a crisp dollar bill and lightly polish the metal rod. The goal is to scrub off the residue without scratching the metal. Do not use sandpaper or an abrasive file! This creates tiny grooves that will cause carbon to build up even faster in the future.
  4. Wipe and Reinstall: Use a dry cloth to wipe away any dust from the cleaning. Carefully place the sensor back in its housing, replace the screw, and ensure the wire is securely reconnected.

Step 4: Restore Power and Test

With the flame sensor clean and the unit reassembled, it’s time to test your work.

  1. Turn the gas supply back on (handle parallel to the pipe).
  2. Flip the circuit breaker back on.
  3. Power on the unit and run a hot water tap.

Listen carefully. You should hear the fan start, the igniter click or glow, and then a “whoosh” as the burner ignites. If the unit stays running and the E513 code is gone, congratulations! You’ve likely solved the problem.

Common Problems with an E513 Navien Tankless Water Heater That Require a Pro

If you’ve cleaned the flame sensor and checked the basics but the E513 error persists, the issue likely lies deeper. This is the point where safety and specialized tools become critical. Here are common problems with an e513 navien tankless water heater that are best left to a licensed technician.

Low or Fluctuating Gas Pressure

Your heater needs a specific, stable gas pressure to operate. If it’s too low, the flame will be too weak to register. A technician will use a special tool called a manometer to measure the pressure and adjust the regulator if needed. This is not a DIY task.

Faulty Ignition Assembly

If the igniter is cracked or failing, it won’t produce a strong enough spark to light the gas properly. A technician can test the igniter’s resistance and replace the entire assembly if it’s out of spec.

A Failing Main Control Board

The control board is the brain of your water heater. If it’s not correctly sending or receiving signals from the sensors and components, it can falsely trigger an E513 error. Diagnosing and replacing a control board is a complex job for a professional.

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Your Eco-Friendly E513 Navien Tankless Water Heater Care Guide

The best way to deal with an E513 error is to prevent it from happening in the first place. Following a simple maintenance schedule not only improves reliability but also ensures your unit runs at peak efficiency, which is the core of any sustainable e513 navien tankless water heater strategy.

Annual Professional Servicing

Have a certified technician service your Navien unit once a year. They will perform a comprehensive check that includes cleaning the flame sensor and igniter, verifying gas pressure, inspecting all safety devices, and cleaning the internal filters. This is the single most effective thing you can do.

Regular Descaling (Flushing)

If you live in an area with hard water, mineral scale can build up inside the heat exchanger, reducing efficiency and straining components. Flushing your unit every 12-18 months with a descaling solution will preserve its health and performance. This is a key part of any e513 navien tankless water heater care guide and supports an eco-friendly e513 navien tankless water heater by maintaining its energy-saving design.

Frequently Asked Questions About the E513 Navien Error

Is it safe to keep resetting my Navien if the E513 code comes back?

No. While a single reset is fine for troubleshooting, repeatedly resetting the unit is not a solution. The error code is a safety alert for a reason. Continuously ignoring it can put stress on other components and mask a potentially dangerous underlying issue. Address the root cause instead.

How much does it cost to fix an E513 error?

The cost varies greatly. If you can fix it by cleaning the flame sensor yourself, your only cost is a few dollars for steel wool. If you need a professional, a standard service call to clean the sensor and perform basic maintenance might cost between $150 and $400. If parts like the control board or gas valve need replacement, the cost could be significantly higher.

Can I use sandpaper to clean the flame sensor?

Absolutely not. We can’t stress this enough. Sandpaper, emery cloth, or abrasive files will scratch the surface of the flame rod. These tiny scratches create more surface area for carbon to cling to, causing the problem to return much faster. Stick to #0000 steel wool or a crisp dollar bill for a smooth, polished finish.

How often should I have my Navien tankless water heater serviced to prevent errors like E513?

We strongly recommend annual professional maintenance. An annual check-up allows a technician to catch small issues like a slightly dirty flame sensor or a clogged filter before they escalate into a no-hot-water emergency and an E513 error code.

Tackling an error code on your own can feel empowering. By following these safe, professional-approved steps, you’ve addressed the most common cause of the E513 error and learned more about how your impressive tankless system works. The true benefits of e513 navien tankless water heater knowledge are confidence and peace of mind.

Remember that preventative maintenance is your best tool for ensuring endless hot water. Whether you handle the basic cleaning yourself or rely on a trusted pro for annual service, you’re investing in the comfort, efficiency, and safety of your home.

You’ve got this! By understanding your system and knowing when to call for backup, you can ensure safe, reliable hot water for years to come. Stay safe and stay comfortable!

David Clark
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