How to Fix Noritz Error Code 16

EC16 or Error Code 16

The 16 error code occurs when the outlet water temperature spikes to an abnormally high value. The heater will restrict its water flow as an additional precaution. The error code is reset by unplugging the heater, waiting 20 seconds, and plugging it back in.  Common causes for the 16 error code are:

• Scale deposits¹ in the heat exchanger² and water components

• Improperly adjusted manifold³ pressures

• Wrong gas type

To fix error code 16, you’ll need the help of a professional and most likely recommend a descale of the tankless water heater.

We recommend installing a water treatment system to prevent error codes like this one in the future.