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Navien Water Heater Error Codes: Meanings & Safe Checks
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E003 Navien water heater E003 means Ignition failure. See the verified model scope, safe checks, and official source. Search/display variants: E003 caution E004 Navien water heater E004 means False flame detection. See the verified model scope, safe checks, and official source. Search/display variants: E004 caution E012 Navien water heater E012 means Flame loss. See the verified model scope, safe checks, and official source. Search/display variants: E012 caution E016 Navien water heater E016 means Overheating of the heat exchanger. See the verified model scope, safe checks, and official source. Search/display variants: E016 caution E030 Navien water heater E030 means Exhaust overheating - the water heater shuts down when the flue temperature exceeds 149 degrees F (65 degrees C). Search/display variants: E030 caution E046 Navien water heater E046 means Abnormal operation: limit control. See the verified model scope, safe checks, and official source. Search/display variants: E046 caution E047 Navien water heater E047 means Abnormal operation: exhaust thermostat. See the verified model scope, safe checks, and official source. Search/display variants: E047 caution E060 Navien water heater E060 means Abnormal operation: dual venturi. See the verified model scope, safe checks, and official source. Search/display variants: E060 caution E109 Navien water heater E109 means Abnormal operation: fan motor. See the verified model scope, safe checks, and official source. Search/display variants: E109 caution E110 Navien water heater E110 means Abnormal air pressure. See the verified model scope, safe checks, and official source. Search/display variants: E110 caution E407 Navien water heater E407 means Hot water outlet: thermistor open or short circuit. Search/display variants: E407 caution E421 Navien water heater E421 means Cold water inlet 1: thermistor open or short circuit. Search/display variants: E421 caution E432 Navien water heater E432 means Cold water inlet 2: thermistor open or short circuit. Search/display variants: E432 caution E434 Navien water heater E434 means Abnormal operation: water adjustment valve. See the verified model scope, safe checks, and official source. Search/display variants: E434 caution E438 Navien water heater E438 means Abnormal operation: circulation pump. See the verified model scope, safe checks, and official source. Search/display variants: E438 caution E439 Navien water heater E439 means Abnormal operation: flow sensor. See the verified model scope, safe checks, and official source. Search/display variants: E439 caution E441 Navien water heater E441 means Hot water inlet 2: thermistor open or short circuit. Search/display variants: E441 caution E445 Navien water heater E445 means Abnormal operation: bypass mixing valve. See the verified model scope, safe checks, and official source. Search/display variants: E445 caution E515 Navien water heater E515 means Abnormal operation: PCB (printed circuit board). See the verified model scope, safe checks, and official source. Search/display variants: E515 caution E517 Navien water heater E517 means Abnormal operation: DIP switch setting. See the verified model scope, safe checks, and official source. Search/display variants: E517 caution E593 Navien water heater E593 means Abnormal operation: front panel key. See the verified model scope, safe checks, and official source. Search/display variants: E593 caution E615 Navien water heater E615 means Abnormal operation: input and memory. See the verified model scope, safe checks, and official source. Search/display variants: E615 caution E736 Navien water heater E736 means Abnormal operation: cascade communication. See the verified model scope, safe checks, and official source. Search/display variants: E736 caution E740 Navien water heater E740 means Abnormal operation: outdoor temperature sensor. See the verified model scope, safe checks, and official source. Search/display variants: E740 caution E760 Navien water heater E760 means Flushing/service alarm. See the verified model scope, safe checks, and official source. Search/display variants: E760 routine E782 Navien water heater E782 means Abnormal operation: main panel communication. See the verified model scope, safe checks, and official source. Search/display variants: E782 caution E785 Navien water heater E785 means Abnormal operation: flow switch/sensor. See the verified model scope, safe checks, and official source. Search/display variants: E785 caution