Troubleshoot Noritz Error Code 90: Combustion Abnormality

Noritz Error Code 90: Combustion Abnormality

A 90 error code indicates a combustion abnormality.

This means that the mixture of fuel and air is off from specification and is resulting in poor quality combustion.

To simplify it, the unit is either struggling to move air in or out of the unit or it is unable to hit the set temperature.

On a newly installed tankless unit giving a 90 error code, the problem more often lies in insufficient gas pressure to the unit, incorrect or poorly installed venting or dipswitches not set correctly for elevation, pipe size or length.

On a unit that has been installed for some time and only recently exhibits the 90 error code, it could still be related to the above but more likely attributed to a dirty unit due to lack of maintenance.

Error Code 90 Video

If you are experiencing the Noritz error code 90, you may take the following actions:

• Contact Amor Plumbing:  Reach out to Amor Plumbing for professional assistance to diagnose and resolve the issue effectively. We service all customer in the following counties: Santa Clara, Alameda County, Contra Costa, and San Mateo County.

  
  

• You can reach Amor Plumbing in the following ways:

  • Online Contact Form: Submit your inquiry through our online contact form

  • Phone Call: Give us a call at (408) 649-3129

  • Text Message: Send a text to (408) 649-3129 include your Noritz model, serial number and a photo of your installation for faster assistance.

• Use the Noritz Contractor Locator: Visit the Noritz website to use their contractor locator tool to find a certified technician or plumber near you.

If you are uncertain about the coverage of your Noritz tankless water heater, contact Noritz Technical Service at 866-766-7489.