Navien Tankless Water Heater Standby Mode [Explained]

Navien tankless water heater standby mode means that your heater has power and it’s operational but it’s not currently heating any water. The heater goes into this mode when there’s no demand for hot water to save energy.

The newer generation of Navien heaters has made it really easy to know when you’re in standby mode. Your heater’s display panel will be of green color to represent that you’re currently in this mode.

navien tankless water heater standby mode

Unfortunately, your heater can also get stuck in this standby mode at times. Keep reading this guide to learn in detail about this mode and how you can get out of it. So, let’s dive in!

Apart from the Standby mode, your heater can be in two other modes. These two modes are operational and error mode. Let’s have a better understanding of them as they’re all related to each other.

Note: You can read our guide on navien tankless water heaters no hot water.

i). Operational Mode

You can tell by the name that the operational mode means everything is fine with your water heater. It has power, it’s currently in action and producing hot water.

navien tankless water heater operational mode

In the newer Navien models, the display panel will be blue when the heater is in operational mode. Here’s how it looks:

ii). Error Mode

The error mode is the polar opposite of the error mode. When the heater has an error and it’s not functioning, the heater goes into this mode. It means that your heater needs maintenance or repair before it can be used again.

You’d have an easier time dealing with this error mode if you have one of the newer generation Navien units. That’s because the display panel turns red when it goes into error mode and it’ll show the reason behind that error in simple readable text. Check the picture below to see how it looks.

navine tankless water heater has an error mode

The previous models of Navien tankless water heaters only showed error codes when they went into error mode but didn’t state what the issue was. You’d have to look up the meaning of the codes in the owner’s manual. If you’re in error mode, you’ll have to fix the issue to get your heater to work again.

iii). Standby Mode

Now, let’s address the elephant in the room as you’ve already learned about the two other modes. When you turn your Navien water heater on, it’ll go into standby mode by default.

navien tankless water heater standby mode

The first thing it’ll do is run a diagnosis and look for any potential issues with the heater. If it finds out that anything is wrong with the heater, it’ll go into error mode.

But if it doesn’t find any fault, it’ll be ready to get into operational mode. The single most important factor that determines whether the heater will actually get into operational mode is if there’s a demand for hot water.

If there’s no demand for hot water, the heater will just stay in standby mode. It’ll be ready to go into operational mode whenever there’s a need for hot water. But if there’s no demand, then there’s no point in wasting energy and increasing your utility bills. It’s a great feature of the Navien units.

Open a hot water faucet if you’re unsure whether there’s a demand for hot water. As soon as you do that, the heater should go into operational mode.

opening a hot water faucet

Keep in mind that the heater will only go into operational mode if it needs to use energy to heat the water. If you’ve recently used hot water and its temperature is already at your desired level, the heater won’t get into operational mode right away.

Sometimes, the heater can get stuck in standby mode due to other reasons even when you need hot water. Keep reading to know how you can deal with it.

You’d understandably be very worried if your Navien water heater is stuck in standby mode. Even if opening a hot water faucet doesn’t initiate the demand for hot water, you’re in a bit of a pickle.

You won’t get any hot water or would soon stop getting hot water if this happens to your heater. So, how do you get out of it? Here are the things you should try to escape the Navien standby mode:

1. Reset The Heater

The main reason that your heater gets stuck in the standby mode is due to glitches. So, you can easily solve it by resetting the heater. Navien tankless heaters are super easy and intuitive to reset.

reset the navien tankless water heater heater

Before you press the reset button, double-check that your heater has power by looking at the display. Once you press the button and the heater powers back on, increase the temperature of the hot water to initiate the demand for hot water and get out of standby mode ASAP.

2. Reduce Hot Water Usage

Another reason that you’d get stuck in standby mode is if your heater is unable to keep up with your hot water demands. If there are too many people using hot water faucets at the same time, the heater won’t be able to provide such a high amount of hot water.

reduce hot water usage

When that happens and the heater is pushed too hard to do so much work, it resorts back to standby mode. So, you can limit the hot water usage in your house to counter this issue. If that’s not an option, you can install a small hot water tank. Better yet, you can get an additional heater for a long-term fix.

3. Dial Down The Hot Water Temperature

Navien tankless water heaters can also get stuck in standby mode if you set the hot water temperature too high. As you may already know, there are defense mechanisms within the heater to prevent scalding.

reduce the navien tankless water heater temperature

If you set the temperature to a level that’s extremely high, it can trigger that safety feature. The heater will get caught up in standby mode. If you think that could have happened in your case, all you have to do is to reset the heater and bring down the temperature to a safe level.


Where is the reset button on a navien tankless water heater?

Navien tankless heaters have a button called “Reset” on the keypad and that is the reset button. In the newer models, the button doesn’t say “Reset” but looks like a pointer. That’s the reset button in those heaters.

What temperature should I set my Navien tankless water heater?

If you set the temperature above 120°F, it can cause scalding. You can turn up the temperature to get hot water quicker. But make sure that you use thermostatic mixing valves to prevent accidental burns.

How to clean the filter on a Navien tankless water heater?

You’d have to drain the heater first so that you can safely remove the filter. Then, clean the filter with running water. If there’s still dirt on it, scrub it with a brush. Once you’re happy, reinstall it and you’re done.

How to turn off Navien tankless water heater?

There’s a power switch on the keypad of the Navien tankless water heaters. If you press that, the heater will turn off. Unplug the heater from the power outlet as well if you want to service it.


What does the Navien tankless water heater standby mode mean and what can you do if your heater is stuck in this mode? Hopefully, now you know the answer to both these questions in detail. If you implement all the steps in this guide, there’s a 99% possibility that you’ll get out of this mode.

However, if you’re still stuck in it, there could be a more serious issue. Ideally, you should consult a qualified technician in that case. Drop a comment if you have any more questions about Navien tankless heaters.

About David

David is a man who loves doing research and finding out the best solution to any type of heating appliance issues like heaters and fireplaces. Whenever he finds the perfect solutions to any issues of heating appliances after doing in-depth research, he loves to share them with his readers. In fact, his aim is to help his readers to fix the issues with their heating appliances easily.More about us .

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