HeatingCodesNoritz tankless error codes
Noritz tankless water heaters show an error code on the remote controller. Noritz itself says to always err on the side of caution and contact a licensed contractor.
What this table coversThe seven most common Noritz error codes as described in a 2015 post on the Noritz website. The post does not list model numbers. Use your own owner manual for the full list for your model.
How to read the display
Noritz says these codes can diagnose problems that might otherwise go unnoticed until the unit fails, and that you should check that the gas is on and then call a licensed contractor for most of them.
Noritz code table
| Code | Meaning | What the document says |
|---|---|---|
| 11 | Ignition failure | Can be caused by insufficient gas supply, insufficient airflow or debris on the ignition plug. After checking that the gas is on, call a licensed contractor. Full explanation |
| 12 | Weak flame | Similar to 11, caused by lack of gas or airflow. Call a licensed contractor. Full explanation |
| 16 | Sharp spike in outlet water temperature | Often caused by scale buildup. Descaling or a water softener may resolve it. |
| 29 | Condensate drainage problem | Applies to condensing models. A blockage or incorrect condensate drain piping. A contractor should check the drain line. |
| 73 | Improper circuit board settings | Changing a jumper or dip switch while the heater has power can cause it. Noritz says to unplug the heater for 30 seconds and plug it back in, and call a contractor if it persists. |
| F76 | Communication breakdown between two heaters using the Quick Connect Cord | Make sure only one remote control is hooked up when two units are connected. |
| 90 | Combustion abnormality (improper air and fuel mixture) | Needs a licensed contractor. Possible causes are insufficient gas supply, a blocked vent or debris in the fan motor. |
Source: Noritz blog post "How To Resolve The Seven Most Common Noritz Tankless Error Codes" (November 16, 2015).
Detailed explanations
SafetyThese tables describe what the manufacturer documents say. Gas, combustion, refrigerant and line-voltage repairs are for licensed professionals. If you smell gas, leave the building and call your gas utility or 911. Safety disclaimer.
Sources
- How To Resolve The Seven Most Common Noritz Tankless Error Codes (blog, November 16, 2015) (Noritz) Covers: Noritz tankless water heaters in general. The post does not list model numbers, and some codes (for example 29) only apply to condensing models.