How To Turn Off A Navien Tankless Water Heater – A Complete Guide

Whether you’re heading out for a well-deserved vacation, getting ready for routine maintenance, or facing an unexpected issue, knowing how to safely power down your Navien tankless water heater is a crucial homeowner skill. It might seem like a complex piece of equipment, but the process is more straightforward than you think.

Don’t worry, we’re here to walk you through it just like a technician would at your home. This guide will give you the confidence to handle your unit like a pro, ensuring safety and protecting your investment. We’ll cover everything from a simple temporary shutdown to a complete power-down for extended trips and the critical steps for an emergency.

By the end of this article, you’ll have a clear understanding of the entire process. Let’s get you in control of your hot water system.

Why and When You Should Turn Off Your Navien Heater

Before we jump into the “how,” let’s talk about the “why.” A tankless water heater isn’t like an old storage tank model that’s constantly burning fuel to keep 40 or 50 gallons of water hot. Navien units are on-demand, meaning they only fire up when you turn on a hot water tap.

So, why would you ever need to turn it off? Here are the most common scenarios:

Extended Vacations: If you’ll be away for a week or more, a complete shutdown saves a small amount of electricity (phantom power) and eliminates any risk of water leaks while you’re gone. This is a key part of any sustainable and eco-friendly how to turn off a navien tankless water heater plan.
System Maintenance: For tasks like flushing the unit to remove mineral scale (a critical part of any how to turn off a navien tankless water heater care guide), you must perform a full shutdown to work on it safely.
Emergency Situations: If you suspect a gas leak, see a major water leak from the unit, or encounter a critical error code, an immediate shutdown is your first line of defense.
System Reset: Sometimes, a simple power cycle (turning it off and on again) can resolve minor glitches or error codes.

Understanding these reasons helps you choose the right shutdown method for your situation, which is one of the most important how to turn off a navien tankless water heater tips we can offer.

Before You Begin: A Quick Safety Check

Safety always comes first. Before you touch your water heater, take a moment to get your bearings. This is what we technicians do on every single service call.

First, make sure the area around your Navien unit is clear, dry, and well-lit. You’ll need easy access to the unit itself and the pipes connected to it.

Identify These Three Key Connections:

The Gas Line: Look for a flexible or black iron pipe leading to the bottom of the unit. It will have a shutoff valve with a handle, usually painted yellow or red.
The Water Lines: You will see three pipes. One is the cold water inlet (usually marked blue), one is the hot water outlet (usually marked red), and the third is the pressure relief valve drain line. Each will have its own shutoff valve.
The Electrical Supply: Your Navien unit is plugged into a standard wall outlet or hardwired. Trace this cord or conduit back to your home’s main electrical panel and identify which circuit breaker controls it. It’s a great idea to label this breaker now if it isn’t already.

Pro-Tip: Keep your Navien user manual in a safe, accessible place. It’s an invaluable resource for model-specific information and troubleshooting error codes.

CRITICAL SAFETY WARNING: If at any point you smell gas (a rotten egg or sulfur smell), STOP IMMEDIATELY. Do not touch any electrical switches. Leave the house, and from a safe distance, call your gas utility’s emergency line and a certified HVAC professional.

The Simple Shutdown: Using the Control Panel for Short Absences

Let’s start with the easiest method, perfect for when you’re leaving for a long weekend. This puts the unit into standby mode.

Most modern Navien models (like the NPE and NPN series) have a sleek front control panel with a power button. This is your first and simplest option.

Step-by-Step Standby Mode:

Locate the Power Button: On the front display of your unit, find the physical power button. It’s often marked with the universal power symbol (a circle with a vertical line).
Press and Hold: Press and hold the power button for a few seconds. The screen will go blank or display an “OFF” message.
Confirm It’s Off: The unit is now in standby. It will not heat water if you turn on a tap.

In this state, the unit still has electrical power. This is important because it allows the built-in frost protection to activate if temperatures drop, preventing the water inside the unit from freezing and causing catastrophic damage. This is the recommended method for short-term absences in colder climates.

The Complete Guide on How to Turn Off a Navien Tankless Water Heater for Vacations or Maintenance

For longer trips, annual maintenance like descaling, or if you want total peace of mind, a complete shutdown is the way to go. This involves shutting off the power, gas, and water supplies in a specific order.

Here is the complete how to turn off a navien tankless water heater guide that professionals follow.

Step 1: Power Down the Control Panel

Just as we did in the simple shutdown, start by pressing and holding the power button on the front of the unit until the display turns off. This ensures the unit’s internal components shut down gracefully.

Step 2: Shut Off the Gas Supply

This is a critical safety step. Find the gas shutoff valve on the pipe leading to your heater. The handle will be parallel to the pipe when it’s open.

To close it, give the handle a quarter-turn so that it is perpendicular to the pipe. Think of it this way: when the handle crosses the pipe, it’s blocking the flow. Righty-tighty, lefty-loosy doesn’t apply here—it’s all about the position.

Step 3: Shut Off the Water Supply

Now, let’s stop the water flow. Your unit has service valves on the cold and hot water lines. They might have T-shaped handles or long lever handles.

Turn the handle on the cold water inlet (blue) clockwise or give the lever a quarter-turn until it is perpendicular to the pipe.
Do the same for the hot water outlet (red).

Step 4: Disconnect the Electrical Power

This is the final step for a complete shutdown. Go to your home’s main electrical service panel (breaker box).

Locate the breaker labeled “Water Heater,” “Tankless,” or “Navien.” Flip the switch to the “OFF” position. If your unit has a power cord, you can also simply unplug it from the wall outlet after turning off the breaker for double safety.

Your Navien tankless water heater is now fully and safely turned off. This is one of the most important how to turn off a navien tankless water heater best practices for ensuring longevity and safety.

Restarting Your Navien Unit Safely and Correctly

Turning the unit back on is just as important as turning it off. You need to follow the steps in reverse order to prevent air pockets in the lines or error codes.

Restore Water Flow: Go back to the unit and slowly turn the handle on the cold water inlet valve first. Let the unit fill with water. Then, slowly open the hot water outlet valve. Now, go to a nearby sink and turn on a hot water tap until you get a steady, air-free stream of water. This purges any air from the system.
Restore Electrical Power: Go to your breaker panel and flip the water heater’s breaker back to the “ON” position. If you unplugged it, plug it back in.
Restore the Gas Supply: This is a key step. Turn the gas valve handle a quarter-turn so it is once again parallel with the gas pipe. Do a quick “sniff test” around the connection to ensure you don’t smell any gas.
Power On the Unit: Press the power button on the front control panel. The display should light up, and the unit will go through a brief startup cycle.
Test for Hot Water: Turn on a hot water tap. It may take 30-60 seconds for the unit to fire up and deliver hot water to the faucet, which is completely normal.

If you encounter any common problems with how to turn off a navien tankless water heater and turning it back on, like a persistent error code, consult your manual or call a certified technician.

Frequently Asked Questions About How to Turn Off a Navien Tankless Water Heater

Do I need to turn off my Navien for a weekend trip?

No, it’s not necessary. For short trips of just a few days, simply using the power button on the control panel to put the unit in standby mode is sufficient. This keeps the valuable frost protection feature active while preventing the unit from heating water unnecessarily.

What happens if I just unplug it without shutting off the gas and water?

While this will turn the unit off, it’s not the recommended procedure. You leave the gas and water lines pressurized to the unit. If a slow leak were to develop, it could go undetected. Following the proper shutdown sequence is a much safer practice, especially for long-term shutdowns.

My Navien unit doesn’t have a power button on the front. How do I turn it off?

Some older or more basic models may not have a prominent power button on the display. In this case, the primary way to turn off the unit is by shutting off the power at the circuit breaker. For a complete shutdown, you would still follow the same sequence: turn off the breaker, then shut off the gas and water valves.

I turned my heater back on, but I’m getting an error code. What should I do?

First, don’t panic. Try a simple reset by turning the unit off at the control panel, waiting one minute, and turning it back on. If the error code returns, write it down and consult your user manual. The manual will tell you what the code means and suggest troubleshooting steps. If the issue persists or it’s a critical code, it’s time to call a Navien-certified technician for help.

You’ve just walked through the complete process for managing your Navien tankless water heater. From short trips to long vacations and even maintenance prep, you now have the knowledge to do it safely and effectively.

Remember to always prioritize safety by following the steps in the correct order, and never hesitate to call a professional if you feel unsure or smell gas. Taking proper care of your equipment is the best way to ensure you have reliable and efficient hot water for years to come.

You’re now equipped to manage your Navien unit with confidence. Stay safe, and enjoy that endless hot water!

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David Clark

Founder & Lead HVAC Specialist at HVACRLY

David Clark is the founder of HVACrly and a certified HVAC specialist with 10+ years working on residential and light-commercial systems. He turns complex heating, cooling, ventilation, and refrigeration topics into clear, actionable guides focused on safety and energy efficiency. When he’s not on a service call, he’s testing tools and writing step-by-step tutorials.