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 deposits in the heat exchanger and water components.
- Wrong gas type.
NRCR specific causes:
- NRCR used in dedicated recirculation system: The cold water supply and hot water return line are connected in reverse. Correct the plumbing
- NRCR used in a crossover system: The cold water supply line is connected to only hot water return. Branch the cold water supply to the hot water return connection as shown in the installation manual.
Other less likely causes related to all Premix models:
- Damaged or improperly connected heat exchanger or hot water thermistor.
- Malfunctioning or incorrectly adjusted gas valve.
- Damaged or improperly connected main or bypass water control servo.
For further technical assistance call 866-766-7489 or use our Contractor Locator to find a local service representative.