Rheem Tankless Water Heater Code 11: Your Quick and Easy Fix Guide

If you’re experiencing intermittent water heating or no hot water at all from your Rheem tankless water heater, it’s likely that you’re encountering Code 11. This code indicates a problem with the water flow sensor, which monitors the flow of water through the unit and ensures that it operates safely and efficiently.

Understanding Code 11

Code 11 appears on the digital display of your Rheem tankless water heater. It signifies that the water flow sensor has detected an issue, preventing the unit from heating water. This code can be caused by various factors, including:

• Insufficient water flow
• Clogged water filter
• Faulty water flow sensor
• Air in the water lines

How to Fix Rheem Tankless Water Heater Code 11

1. Check Water Flow

Ensure that there is adequate water pressure flowing into the water heater. Open a faucet and observe the water flow. If the flow is weak or intermittent, there may be a problem with your water supply or plumbing system.

2. Clean Water Filter

Locate and clean the water filter on the cold water inlet line. A clogged filter can restrict water flow, triggering Code 11. Remove the filter and rinse it thoroughly with clean water.

3. Inspect Water Flow Sensor

The water flow sensor is usually located near the cold water inlet. It consists of a paddle or impeller that rotates when water flows through it. Inspect the sensor for any debris or obstructions that may be hindering its movement.

4. Reset Water Flow Sensor

Try resetting the water flow sensor by following these steps:

• Turn off the power to the water heater.
• Close the cold water inlet valve.
• Open a hot water faucet to release any remaining pressure.
• Turn on the cold water inlet valve.
• Turn on the power to the water heater.

5. Check for Air in Water Lines

Air in the water lines can cause erratic water flow, which can trigger Code 11. To remove air from the lines, open all the hot water faucets in your home and let them run for a few minutes until the air is purged.

6. Replace Water Flow Sensor

If cleaning or resetting the water flow sensor does not resolve the issue, it may need to be replaced. You can purchase a replacement sensor from an authorized Rheem dealer or online.

7. Contact a Qualified Technician

If you have tried all the above steps and Code 11 persists, it’s recommended to contact a qualified HVAC technician. They can diagnose the underlying problem and perform any necessary repairs or replacements.

Wrapping Up

Resolving Rheem tankless water heater Code 11 can be a straightforward task if you follow the steps outlined in this guide. By addressing the issue promptly, you can restore hot water to your home and prevent further damage to your water heater. If you encounter any difficulties or require professional assistance, don’t hesitate to seek the help of a qualified technician.

Information You Need to Know

What causes Rheem tankless water heater Code 11?

Code 11 is caused by insufficient water flow, a clogged water filter, a faulty water flow sensor, or air in the water lines.

Can I fix Rheem tankless water heater Code 11 myself?

Yes, you can attempt to fix Code 11 yourself by following the steps in this guide. However, if the issue persists or you are not comfortable performing the repairs, it’s best to contact a qualified technician.

How much does it cost to fix Rheem tankless water heater Code 11?

The cost to fix Code 11 will vary depending on the underlying cause. If it’s a simple issue like cleaning the water filter, it may cost around $20 for the filter. However, if the water flow sensor needs to be replaced, the cost could range from $100 to $250 for the part and labor.