Tank and tankless water heaters monitor burner combustion, gas pressure, and water temperature. Access our technician test protocols for pilot assemblies and thermostats.
We couldn't find documented codes for the selected brand in Water Heaters & Tanks.
Applies to: Rheem Performance Platinum Gas Water Heater
The Flammable Vapor Sensor (FVS) detects volatile hydrocarbons near the water heater base or sensor resistance is outside the normal calibrated range (9–45 kΩ).
Applies to: Bradford White Defender Safety System Gas Water Heater
The electronic gas control valve detects thermopile voltage below the minimum operating threshold (less than 350 millivolts DC under pilot flame).
Applies to: AO Smith Signature Premier Electric Water Heater
The electronic thermostat board detects an open circuit (infinite resistance) through the upper electric heating element, often caused by element burnout or dry-firing.
Applies to: Navien NPE-A2 / NPE-S2 Condensing Tankless
Ignition failure (E003). The tankless water heater attempted 3 ignition sequences, but the flame ionization rod failed to sense burner flame presence.
Applies to: Rinnai Sensei RU199i / RL94i Tankless Water Heater
Ignition failure (Code 11). The water heater attempted to light the burner upon water flow demand, but flame was not detected at the ionization sensor.
Applies to: Rheem Gladiator Smart Electric Water Heater
Lower temperature sensor failure. The smart control module detects that the resistance of the lower NTC thermistor is out of normal operating range (shorted or open circuit).
Prior to performing any diagnostic testing or taking electrical measurements on residential or commercial equipment, always lock out / tag out (LOTO) power sources and shut off fuel or water supplies. Wear rated personal protective equipment (insulated gloves, eye protection) and use a calibrated CAT III/CAT IV digital multimeter.
If fault symptoms persist after executing our pinout checks and component resistance tests, consult a factory-certified technician or licensed HVAC/appliance specialist.