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

 For assistance with this error code visit to find a local service representative.


A hard mineral coating which forms on the surfaces of water piping. Scaling is more prevalent in areas with high water hardness.

Heat Exchanger2
A device used to transfer thermal energy between two or more fluids (e.g. air, water, oil). The fluids are typically separated and not allowed to mix.

A main pipe that accepts or distributes water to and from multiple sources -or- a heater component which distributes gas to the burner plates

Updated on April 12, 2021

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