Tankless Water Heater Error Codes

41 tankless water heater codes across 2 brands. Jump to yours:

Navien Tankless Water Heater Codes19

• E003 E003 — Ignition Failure
• E003C E003C — Cascade Ignition Failure
• E012 E012 — False Flame / Flame Loss
• E016 E016 — Overheat / High-Limit Trip
• E027 Tankless E027 — Sensor Abnormality
• E030 E030 — Abnormal Exhaust Temperature (Flue Overheat)
• E046 E046 — Abnormality in Limit Control (Heat-Exchanger High-Limit)
• E109 E109 — Fan Motor Abnormal Operation
• E110 E110 — Exhaust Blockage / APS Fault
• E193 E193 — Condensate Drain Blockage
• E351 E351 — Water Flow Sensor Fault
• E406 E406 — Heat Exchanger Scale / Lime Buildup
• E432 E432 — Outlet Thermistor Fault
• E438 E438 — Abnormal Circulation Pump Operation
• E515 E515 — PCB / Control Board Abnormal
• E594 E594 — Gas Valve / Modulation Fault
• E615 E615 — Abnormal Input/Memory (MCU Internal Fault)
• E760 E760 — Water Leak Detected
• E777 E777 — Dip Switch Setting Error

Rinnai Tankless Water Heater Codes22

• 02 02 — Power Interruption / Memory Loss
• 03 03 — Loss of Communication / EZConnect Issue
• 10 10 — Air Supply or Exhaust Blockage
• 11 11 — No Ignition
• 12 12 — Flame Failure
• 14 14 — Thermal Fuse / Overheat Cutoff
• 16 16 — Outgoing Water Over-Temperature
• 25 25 — Condensate Drain Blocked (Condensing Models)
• 31 31 — Burner Sensor (Combustion Offset) Fault
• 32 32 — Outgoing Water Thermistor Fault
• 33 33 — Heat Exchanger Thermistor Fault
• 34 34 — Combustion Air Temperature Sensor Fault
• 51 51 — Gas Solenoid Valve Fault
• 52 52 — Modulating Solenoid Valve Signal Abnormal
• 61 61 — Combustion Fan Motor Fault
• 65 65 — Water Flow Control Valve Fault
• 70 70 — PCB / Control Board Fault
• 71 71 — Gas Solenoid Drive Circuit Fault
• 72 72 — Flame Sensor Fault
• 90 90 — Combustion Abnormality
• 99 99 — Exhaust Blockage / Fan Issue
• LC LC — Scale Buildup / Descale Reminder

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