How To Turn On Navien Water Heater - Your Complete Guide To Safe

There it is, your high-efficiency Navien tankless water heater—silent and still. Maybe you’ve just moved in, the power just came back on, or you’re returning from a long vacation. You turn a faucet, expecting steaming hot water, but all you get is cold. It’s a common moment of confusion for many homeowners.

Don’t worry, we’ve been there. That quiet digital display can seem intimidating, but getting your hot water flowing is usually straightforward and safe when you know the steps. You’re in the right place to get clear, expert advice.

We promise this comprehensive how to turn on navien water heater guide will walk you through the entire process, from essential safety checks to understanding the control panel and troubleshooting common hiccups. We’ll empower you to handle the startup confidently and know exactly when it’s time to call for backup.

Let’s get that hot water running so you can get back to your day. We’ll cover everything from the basic power-up sequence to best practices for keeping your unit in top shape.

Before You Begin: Essential Safety Checks for Your Navien Heater

Before you press a single button, let’s talk safety. As an HVACR professional, I can’t stress this enough: a few moments of prevention are worth their weight in gold. These checks ensure your unit is ready to operate safely.

1. Check for Gas Leaks (The Sniff Test)

This is the most critical first step. Natural gas has a distinct rotten egg smell (an additive called mercaptan) for a reason. Walk up to your Navien unit and take a slow, deliberate sniff around the unit and its gas connections.

If you smell anything like rotten eggs, STOP IMMEDIATELY. Do not touch any electrical switches, unplug anything, or use your phone nearby. Leave the house, and from a safe distance, call your gas company’s emergency line. This is non-negotiable.

2. Verify Water Connections are Open

Your Navien needs water to heat! Locate the water lines connected to your unit. You should see two main valves, typically with red and blue handles or tabs.

The blue handle is the cold water inlet.
The red handle is the hot water outlet.

Ensure both valves are in the “open” position. For lever-style handles, the handle should be parallel to the pipe. For round, faucet-style handles, turn them counter-clockwise until they stop.

3. Ensure Proper Power and Venting

Take a quick look around the unit. The power cord should be securely plugged into a dedicated electrical outlet. Don’t use extension cords.

Next, glance at the PVC pipes leading out of the top or side of your unit. These are the intake and exhaust vents. Make sure they are clear of any obstructions like bird nests, leaves, or snow. Proper airflow is essential for safe and efficient operation.

The Core Steps: How to Turn On Navien Water Heater Like a Pro

With the safety checks complete, you’re ready for the main event. If you’ve been searching “how to how to turn on navien water heater,” this step-by-step process is your answer. We’ll make it simple.

Open the Main Gas Supply Valve
Follow the flexible gas line from your Navien unit back to the main gas pipe. You’ll find a shut-off valve there, usually with a yellow or red handle. Like the water valves, the handle should be turned so it is parallel with the gas pipe to be in the open position. If it’s perpendicular, it’s closed.
Plug In the Unit and Turn On the Power Button
If it isn’t already, plug the Navien’s power cord firmly into its wall outlet. Now, look at the front control panel. You should see a power button, often marked with the universal power symbol (a circle with a vertical line). Press it once.
The display should light up, and the unit will begin its startup sequence. You might hear some clicks and the sound of a small fan—this is completely normal.
Set Your Desired Water Temperature
The default temperature is often 120°F, which is recommended by the Department of Energy for a good balance of safety and performance. If you need to adjust it, use the “Up” and “Down” arrow buttons on the control panel. Most Navien models allow a range from about 98°F to 140°F.
Pro Tip: Setting your temperature higher than 120°F increases the risk of scalding and uses more energy. For most households, 120°F is the sweet spot.
Test a Hot Water Faucet
Now for the moment of truth! Go to a faucet close to the water heater, like a laundry sink or nearby bathroom, and turn on the hot water all the way. It won’t be instant—the unit needs to sense the water flow, ignite the burner, and heat the water as it passes through.
Within 15-30 seconds, you should feel the water start to get warm, then hot. Let it run for a minute to ensure you have a steady, consistent flow of hot water. Success!

Understanding Your Navien Control Panel: What the Buttons and Lights Mean

The control panel is your window into the unit’s operation. While models vary slightly, most Navien panels share common features. Understanding them is a key part of our how to turn on navien water heater care guide.

Power Button: Turns the unit on and off.
Up/Down Arrows: Adjust the set temperature for your domestic hot water (DHW).
DHW Button (or similar): Sometimes used to confirm temperature changes or switch between modes. The display will typically show the set temperature and an icon of a flame when the burner is actively heating water.
Status Light: A small LED light often indicates the unit’s status. A solid green or blue light usually means everything is normal. A flashing or red light often signals an issue or an error code.

If you see a number on the screen that isn’t the temperature (like “E.012” or “E.709”), that’s an error code. Don’t panic! It’s the unit telling you exactly what it thinks is wrong.

Common Problems with How to Turn On Navien Water Heater (and How to Fix Them)

Sometimes, even when you follow the steps, things don’t go as planned. Here are a few common problems you might encounter and how to safely troubleshoot them.

Problem 1: The Unit Won’t Power On at All

You press the power button, but the screen stays blank. Nothing happens.

The DIY Check: First, check your home’s circuit breaker panel. Find the breaker labeled “Water Heater” or similar and make sure it’s in the “ON” position. If it has tripped to the middle or “OFF” position, flip it fully off and then back on once.
When to Call a Pro: If the breaker trips again immediately, or if the breaker is on but the unit still has no power, there may be an electrical issue with the unit or the circuit. Do not attempt further electrical diagnosis yourself. Call a qualified technician.

Problem 2: The Unit Powers On, But You Get No Hot Water

The display is lit, but the water stays stubbornly cold.

The DIY Check: Double-check your gas and water valves. It’s easy to miss one. Ensure the main gas valve, the cold water inlet, and the hot water outlet are all fully open (parallel to the pipe). Also, make sure you’re running the hot water at a high enough flow rate—sometimes a slow trickle isn’t enough to activate the unit’s flow sensor.
When to Call a Pro: If all valves are open and you still have no hot water, the issue could be an internal problem like a stuck flow sensor, a faulty igniter, or a gas pressure problem. These require professional service.

Problem 3: An Error Code Appears on the Display

The unit tries to start but then shows an error code.

The DIY Check: Your Navien manual is your best friend here. Look up the specific error code to understand the problem. Some common codes, like those related to low water pressure or a temporary ignition failure, can sometimes be resolved by resetting the unit (unplugging it for 30 seconds and plugging it back in).
Pro Tip: Always write down the error code before you reset the unit. If the problem persists, this code is the most valuable piece of information you can give your service technician.
When to Call a Pro: For any codes related to gas pressure, venting, or internal sensors, it’s safest to call a Navien-certified technician.

How to Turn On Navien Water Heater Best Practices for a Long Lifespan

Getting your heater started is one thing; keeping it running efficiently for years is another. Adopting a few best practices will ensure you get the most from your investment. This is where the sustainable how to turn on navien water heater approach comes in—an efficient heater is an eco-friendly one.

Annual Flushing: In areas with hard water, mineral scale can build up inside the unit, reducing efficiency and lifespan. Flushing your tankless water heater annually with a vinegar solution is the single best maintenance task you can perform.
Keep Vents Clear: Regularly inspect the exterior intake and exhaust vents to ensure they are free from debris, snow, or overgrown landscaping.
Check the Condensate Line: High-efficiency units like Navien produce condensation. Ensure the small drain line is not clogged or frozen, as this can cause the unit to shut down.

The Benefits of Knowing Your System: Why This Guide Matters

Learning the simple steps of how to turn on your Navien heater does more than just get the water hot. There are several benefits of how to turn on navien water heater knowledge.

First, it gives you peace of mind and control. You can confidently handle a simple reset after a power outage without having to wait or pay for a service call. Second, it saves you money by avoiding unnecessary professional visits for simple issues like a closed valve or a tripped breaker.

Finally, understanding the basics of your system’s operation empowers you to spot small problems before they become big, expensive ones. This proactive approach is the cornerstone of responsible homeownership.

Frequently Asked Questions About Turning On a Navien Water Heater

How do I reset my Navien water heater?

The simplest way to perform a “soft reset” is to unplug the unit from the wall outlet, wait for about 60 seconds, and then plug it back in. This can often clear temporary glitches or error codes. If the problem returns, it indicates a more persistent issue that needs attention.

What temperature should I set my Navien to?

For safety and energy efficiency, 120°F (49°C) is the recommended setting for most households. This temperature is hot enough for all domestic needs while significantly reducing the risk of scalding, especially in homes with children or elderly residents.

Why is my Navien water heater making a clicking sound when I turn it on?

A series of clicking sounds during startup is perfectly normal. This is the sound of the gas valve opening and the electronic igniter trying to light the burner. You should hear the clicks, followed by the “whoosh” of the burner igniting. If you hear continuous clicking without ignition, it may signal a problem with the gas supply or igniter.

Is it okay to turn my Navien off when I go on vacation?

Yes, it’s a great idea for saving energy. You can simply press the power button on the front panel to put it in standby mode. If you’ll be gone for an extended period, you can also unplug it and shut off the gas and water valves. Just be sure to follow the full startup procedure in this guide when you return.

You’ve done it! By following these steps, you’ve not only learned how to turn on your Navien water heater but also gained valuable insight into its operation and basic care. Knowing your home’s systems is empowering, and you’re now better equipped to keep your hot water flowing safely and efficiently.

Stay safe, stay comfortable, and enjoy that endless hot water!

Author
Recent Posts

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.