Ao Smith Water Heater E02 Code (2024)

So, you wake up one chilly morning, eager for a hot shower to kick-start your day. But alas, your AO Smith water heater decides to throw a wrench in your plans by flashing the dreaded E02 code. Panic sets in as you wonder what on earth it means and how to fix it. Fear not, dear reader, for we're here to unravel this perplexing code and get your hot water flowing again.

Understanding the AO Smith Water Heater E02 Code

First things first, let's decode what the E02 code actually signifies. In the realm of AO Smith water heaters, error codes like E02 are like cryptic messages from your device, trying to communicate an issue it's facing. In this case, E02 specifically points to a problem with the thermistor.

What's a Thermistor Anyway?

Before diving deeper, let's demystify the thermistor. Think of it as your water heater's temperature sensor. It measures the temperature of the water and communicates this data to the heater's control board. This allows the heater to regulate the temperature and ensure you get that perfect, soothing warmth every time you turn on the tap.

Why Does E02 Pop Up?

Now, you might wonder, why does this error code decide to rear its head? Several factors could trigger the E02 code, including:

  1. Faulty Thermistor: The most common culprit is a malfunctioning thermistor. Over time, these sensors can degrade or become damaged, leading to inaccurate temperature readings and triggering the E02 code.

  2. Wiring Issues: Sometimes, it's not the thermistor itself but the wiring connected to it that's causing trouble. Loose connections or damaged wires can disrupt the flow of data, resulting in error codes like E02.

  3. Environmental Factors: Extreme temperatures or exposure to moisture can also affect the performance of the thermistor, leading to errors.

Troubleshooting the E02 Code

Now that we know what we're up against, let's roll up our sleeves and tackle this issue head-on. Here's a step-by-step guide to troubleshooting the AO Smith Water Heater E02 code:

1. Power Cycle the Heater: Start with the basics. Turn off the power to your water heater, wait a few minutes, and then turn it back on. Sometimes, a simple reset is all it takes to clear the error code.

2. Check the Thermistor: If the E02 code persists, it's time to inspect the thermistor. Locate the sensor (usually near the heating element) and check for any visible damage or signs of wear. If it looks suspect, it might be time to replace it.

3. Inspect the Wiring: While you're at it, examine the wiring connected to the thermistor. Make sure all connections are secure and free of corrosion. If you spot any issues, address them promptly.

4. Contact Customer Support: If the above steps don't resolve the issue, don't hesitate to reach out to AO Smith's customer support. They have a team of experts who can provide guidance and assistance tailored to your specific situation.


In the world of water heaters, encountering error codes like E02 is just par for the course. But armed with a little knowledge and a willingness to troubleshoot, you can overcome these challenges and keep your hot water flowing smoothly. Remember, when in doubt, don't hesitate to seek help from the experts.


Q1: Is it safe to continue using my water heater if it's displaying the E02 code? A1: It's not recommended to use the water heater while it's displaying an error code. Continuing to use it could exacerbate the underlying issue and potentially cause further damage.

Q2: How much does it cost to replace a thermistor in an AO Smith water heater? A2: The cost of replacing a thermistor can vary depending on factors such as the model of your water heater and whether you choose to DIY or hire a professional. It's best to consult with a technician for an accurate estimate.

Q3: Can I reset the E02 code myself, or do I need a technician to do it? A3: In most cases, you can reset the E02 code yourself by power cycling the water heater. However, if the code persists after resetting, it may indicate a more serious issue that requires professional attention.

Q4: How long does it take to replace a thermistor in an AO Smith water heater? A4: The time it takes to replace a thermistor can vary depending on factors such as accessibility and the skill level of the person performing the replacement. In general, it can take anywhere from 30 minutes to a few hours.

Q5: Can I prevent the E02 code from recurring in the future? A5: While some factors that trigger the E02 code may be beyond your control, regular maintenance of your water heater can help prevent issues like faulty thermistors. Inspecting the unit periodically and addressing any issues promptly can go a long way in ensuring its smooth operation.

Ao Smith Water Heater E02 Code (2024)
Top Articles
Latest Posts
Article information

Author: Rueben Jacobs

Last Updated:

Views: 6066

Rating: 4.7 / 5 (77 voted)

Reviews: 92% of readers found this page helpful

Author information

Name: Rueben Jacobs

Birthday: 1999-03-14

Address: 951 Caterina Walk, Schambergerside, CA 67667-0896

Phone: +6881806848632

Job: Internal Education Planner

Hobby: Candle making, Cabaret, Poi, Gambling, Rock climbing, Wood carving, Computer programming

Introduction: My name is Rueben Jacobs, I am a cooperative, beautiful, kind, comfortable, glamorous, open, magnificent person who loves writing and wants to share my knowledge and understanding with you.