Navien Temperature Lock: Control Water Temperature for Safety

Navien is one of the leading tankless water heater company known for its better energy efficiency and advanced technology features. One of these features is the Navien temperature lock, which allows users to control and limit their tankless water heater’s maximum water temperature output. This feature is handy for households with young children or elderly individuals who may be more susceptible to scalding from hot water. Using the temperature lock feature, users can set a maximum temperature limit for their water heater, which helps prevent accidental burns and promotes safety in the home.

In this article, we will explain Navien temperature lock in detail, by covering how it works, its benefits, and how to enable and disable it. We will also answer some FAQs about the temperature lock feature and provide tips for common issues.

In this tutorial we are considering a newer model Navien NPE240A2 where the manual doesn’t have any information about temperature lock. Older or other Navien models have different type of switches so check for the manuals and model before performing.

Steps to Enable Navien temperature lock using DIP switches.

Step 1: Locate the Dip Switches

The first step in enabling temperature lock on your Navien water heater is to locate the dip switches. These switches are typically located on the circuit board of the unit and can be accessed by removing the front panel. You can see the circuit board with DIP switches in the below image.

Navien NPE240A2 DIP switches

As soon as you open the front panel you will see 4 DIP switches on the right side of the controller, and another 2 DIP switches are found at the left side of the controller as seen clearly in the above image.

Step 2: Locate the Temperature Lock Dip Switch

Once you have located the DIP switches, you will need to find the temperature lock switch. Temperature lock switch is present on the left side DIP switches and not on the front side DIP switches. There are two DIP switches on the left side of controller from which switch 2 at bottom is for temperature lock.

Navien NPE240A2 temperature lock switch

From the above image you can see the DIP switch 2 is in ON State which is temperature lock. By default it will be in OFF state.

Step 3: Enable Temperature Lock

To enable temperature lock, flip the switch 2 to the “ON” position. This will activate the temperature lock feature on your Navien water heater, and you cannot change the temperature through controller and its locked.

Step 5: Verify the Temperature Lock Setting

To verify that the temperature lock setting has been enabled and set correctly, you can check the temperature lock indicator on the display by pressing up and down arrow keys which increase or decrease the temperature. The display will show a message “TEMPERATURE LOCK ENABLED”.

navien tankless water heater display with temperature lock enabled

Step 6: Test the Temperature Lock Setting

To test the temperature lock setting, turn on the hot water and verify that the water temperature does not exceed the maximum temperature limit that you have set.


Enabling temperature lock on your Navien tankless water heater is a simple process that can be done using DIP switches. By setting a fixed temperature, you can ensure the safety of your household and prevent accidental burns from hot water if someone increased the temperature without knowing. If you have any questions or concerns about enabling temperature lock on your Navien water heater please comment your concern below, and it is always best to consult a professional tankless water heater expert or HVAC technician.

Frequently Asked Questions:

1. What is the default temperature setting on Navien water heaters?

  • The default temperature setting on Navien water heaters is typically 120°F.

2. Can I change the temperature setting after enabling temperature lock on my Navien water heater?

  • No, once temperature lock mode is enabled, the water temperature is locked and cannot be changed without disabling the temperature lock mode first.

3. Do I need any special tools or equipment to enable temperature lock on my Navien water heater using dip switches?

  • No, you do not need any special tools or equipment to enable temperature lock on your Navien heater, it can be done using dip switches.

4. Is it recommended to enable temperature lock on Navien tankless water heaters?

  • Yes, it is highly recommended to enable temperature lock for safety reasons, especially if there are children or elderly people in the house. It can prevent accidental scalding or burns and give you peace of mind knowing that the water temperature is under control.

5. How do I disable temperature lock on my Navien water heater if needed?

  • To disable temperature lock mode, flip the switch 2 on the left side DIP switches to OFF state.

TanklessHelp Staff

TanklessHelp Staff has an experienced writers and researchers in the field of water heating technology. With a background in HVAC and plumbing, Tanklesshelp staff has in-depth knowledge in many types of waterheaters in America and Canada. They have a passion for educating homeowners and businesses on solving easy to hard repairs and guide them on how to maintain them to save money.

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