Fix Navien Heater Leak: Stop Bottom Drips Fast

Discovering your Navien tankless water heater leaking from the bottom can be a worrying sight. You’re right to be concerned; a leak can indicate several issues, from simple wear and tear to more complex mechanical failures.

In this article, we’ll explore the common causes of leaks in Navien tankless water heaters and provide you with practical steps to diagnose and address the problem. Stay with us to learn how to get your water heater back in top shape and prevent future leaks.

Common Causes of Leaks in Navien Tankless Water Heaters

When you’re facing a pool of water underneath your Navien tankless water heater, you’re likely dealing with one of several common issues. Understanding these can help you pinpoint the problem quickly.

Loose Connections: Pipes and fittings that have not been properly tightened can lead to water trickling down the unit. Regular vibrations and thermal expansion can loosen connections over time, making this a frequent culprit.

Corrosion: While Navien heaters are designed to resist corrosion, factors like hard water can accelerate the process. If corrosion takes hold, small holes might develop, allowing water to escape.

Faulty Internal Components: Items such as the heat exchanger, valves, or pumps can fail and result in leaks. Manufacturers like Navien will often offer warranties on these parts, so knowing the age and warranty status of your heater is key.

Damaged Seals or Gaskets: Over time, the seals and gaskets within the water heater can degrade. This wear and tear are normal but can lead to leaks if not addressed.

It’s important to regularly check these potential problem areas:

  • Inspect connections every few months for tightness
  • Monitor for signs of corrosion, particularly in places with hard water
  • Keep an eye on the condition of seals and gaskets, replacing them as necessary

If you’re regularly maintaining your tankless water heater, you’ll likely prevent leaks before they start. Yet, when you encounter a leak, knowing these common causes empowers you to act swiftly to mitigate damage and restore your heater’s functionality.

Diagnosing the Leak: Where Is It Coming From?

When you’re dealing with a Navien tankless water heater leaking from the bottom, pinpointing the exact location of the leak is crucial for an effective resolution. Start by checking where the water is pooling and trace it to the highest wet point; this is often the leak’s origin.

Loose Connections and Valves

  • Inspect the inlet and outlet water connections
  • Examine the pressure relief valve often found near the bottom

Corrosion or Sediment Build-up

  • Look for signs of rust or white mineral deposits which suggest corrosion or sediment.

Damaged Seals or Gaskets

  • Check the O-rings and gaskets around the water heater’s elements and connections.

Faulty Internal Components

  • See if the internal components such as the heat exchanger are damaged or leaking which could cause water to drip from the bottom.

Remember, wear and tear over time can degrade components, so even without obvious signs like rust, they could still be the issue. Once you’ve identified the problem area, turn off the power supply to your Navien tankless water heater to prevent further damage and consult your manual or a professional for the next steps. Addressing leaks promptly can save you hassle and money in the long run.

Steps to Address a Leak in a Navien Tankless Water Heater

If you’re faced with a leaking Navien tankless water heater, there are several steps you’ll need to take to effectively handle the situation. Remember, acting swiftly can save you from more serious water damage and potentially costly repairs.

Initial Inspection

  • Inspect the unit closely to confirm the leak source.
  • Check for any visible signs of corrosion or damage on the heater’s exterior.

Power Down Before Proceeding

  • Ensure you turn off the electricity or gas supply to your water heater before attempting any repair.
  • For electrical units, switch off the circuit breaker designated to the heater.

Water Supply Shut-Off

  • Locate and close the water valves leading to the heater to stop the flow of water.

Draining the Unit

  • It’s necessary to drain the unit to prevent any water from spilling out during repairs.
  • Attach a hose to the drain valve and direct the water to a suitable location.

Identifying Components

  • Review the Navien manual to identify all components related to the leak.
  • Carefully examine parts like pressure relief valves, heat exchanger, and water inlet, and outlet connections.

Securing Connections and Replacing Parts

  • Tighten any loose connections with suitable tools as these might be the cause of the leak.
  • Replace damaged seals, valves, or gaskets as needed.

Consult a Professional

  • If you’re unsure about any steps, it’s best to enlist the expertise of a certified technician.
  • Regular maintenance by a professional can prevent future leaks.

By tackling each step methodically, you’re ensuring the longevity of your tankless water heater and maintaining its effectiveness. Remember to adhere to the manufacturer’s guidelines and safety measures throughout the process.

Preventing Future Leaks in Your Navien Tankless Water Heater

Maintaining your Navien tankless water heater is critical to preventing future leaks. Regular maintenance checks by a certified technician ensure all components function properly and can save you from the hassle and expense of unexpected repairs. Here are actionable tips to keep your heater in top condition:

  • Schedule Annual Inspections: Have a professional check your unit once a year. They’ll spot any potential issues before they lead to leaks.
  • Soften Hard Water: If you live in an area with hard water, consider installing a water softener. Hard water can cause mineral buildup in your heater, which may eventually lead to leaks.
  • Replace Worn Parts: Keep an eye on the condition of parts like the heat exchanger, O-rings, and valves. If these parts show signs of wear, they need replacing to prevent leaks.
  • Check the Pressure Relief Valve: Ensure this valve is operating correctly to avoid pressure build-up that might cause your unit to leak.
  • Look Out for Corrosion: Regularly check for signs of corrosion and take immediate action to address it since corrosion can weaken the unit and cause leaks.

By following these steps and respecting the maintenance schedule recommended by Navien, you’ll greatly reduce the risk of future leaks. Take note that consistent care extends your unit’s life and keeps it running efficiently.


You’ve got the know-how to tackle a leak from your Navien tankless water heater and understand the value of quick action. Regular maintenance is your best defence against future issues, ensuring your unit operates smoothly for years to come. By sticking to annual inspections and being proactive about the health of your water heater, you’ll safeguard your home from unexpected leaks and the expenses that come with them. Remember to soften hard water, replace parts when necessary, monitor the pressure relief valve and keep an eye out for signs of corrosion. Stay vigilant and your Navien tankless water heater will continue to provide you with reliable service.