Descaling a Noritz Tankless Water Heater Without a Code 11 Alert

Maintaining a Noritz tankless water heater is critical for its longevity and efficiency. One key maintenance task is descaling, particularly when you aren't prompted by a code 11 error, which indicates ignition failure potentially due to scale buildup. Here’s a step-by-step guide to descaling your unit proactively:

1. Turn Off the Power: Safety first! Always start by turning off the electrical power to your tankless water heater.
2. Close Gas and Water Valves: Shut off the gas valve to the unit and the water valves that control the flow to and from the water heater.
3. Prepare Descaling Solution: Mix a commercial descaling solution or prepare a vinegar solution (4 gallons of white vinegar are typically recommended).
4. Connect Pump: Attach a submersible pump to one of the water heater's valves and place it into the bucket containing your descaling solution.
5. Run Descaling Solution: Open the remaining valves and circulate the descaling solution through the system using the pump. This process should run for approximately 45 to 60 minutes.
6. Flush the System: Once descaling is finished, flush the system with fresh water to remove any remaining solution.
7. Close Valves and Reconnect: Close all service valves, disconnect the pump, and make sure to reconnect any lines that were detached during the process.
8. Turn Everything Back On: Finally, reopen the water and gas valves, and restore power to the unit. Watch for any error messages and ensure the water heater is working properly.

Additional Tips

• Always refer to your specific Noritz model's manual for any particular instructions regarding descaling.
• Wear safety glasses and gloves to protect from any splashes of descaling solution.
• If you’re not comfortable performing this maintenance, contact a professional to do it safely and correctly.

Routine descaling can greatly extend the life and improve the performance of your Noritz tankless water heater, even in the absence of a code 11 error.