It means that your unit is not firing up to heat the water, a situation that can be caused by insufficient gas supply, insufficient airflow or debris on the ignition plug. ... He or she will make sure your gas valve is open, the exhaust vent is unobstructed and the ignition plug is firmly attached and free of debris.Nov 16, 2015
How do you program a Noritz tankless water heater?
https://www.youtube.com/watch?v=Y6mFLOLroOU
What is priority light on Noritz tankless water heater?
Also, an indicator shows when the burner is ON and a priority indicator, so when it is lit, the hot water temperature can be set. The display will flash when you press the flow meter alarm set button. If there is a problem with the water heater, an error code (11, 90, 99...) will appear.