Bosch tankless water heater error codes Canada.

Bosch tankless water heater error codes. Bosch hot water heaters are fitted with self diagnostics electronics. When a fault occurs, the heater will shut down and the fault with a pair of digits will be displayed on the display screen. See the following table below for the most likely cause and suggested repair service.

Bosch Error Code 29 Check this : Something in the units’ neutraliser is clogged. Item to check : Try resetting the controller by turning the main power off and on.

Bosch Error Code 90 Check this : Abnormal combustion or law gas supply pressure. Item to check : Turn the control unit off, turn the hot water tap on and turn the control unit on.

Bosch Error Code 92 Check this : The water heater’s neutraliser is in need of replacement. Item to check : Get in touch with a plumber to replace the neutraliser.

Bosch Error Code 99 Check this : Your hot water system has shut down due to abnormal combustion. Item to check : If turning the main power off and on again does not work, you will need to get in contact with a qualified plumber with experience in hot water systems.

Bosch Error Code A1 Check this : There is a problem with your heaters hot and cold sensors. Item to check : Turn the unit off, turn on the hot water tap and turn the power back on. Replace the sensor and/or wire is problem persists.  

Bosch Error Code A2 Check this : The temperature within the hot water unit is hotter than average. Item to check : Call a qualified plumber.

Bosch Error Code A3 Check this : Fault in the flue gas limiter Item to check : Call a qualified plumber.

Bosch Error Code A4 Check this : Wire harness defect. Item to check : Call a qualified plumber.

Bosch Error Code A5 Check this : The air temperature sensor is faulty. Item to check : Call a qualified plumber  

Bosch Error Code A6 Check this : Condensing unit flue temperature sensor disconnected or damaged Item to check : Replace the sensor and/or wire connections with the help of a qualified plumber.

Bosch Error Code A7 Check this : Inlet cold water temperature sensor disconnected or damaged. Item to check : Replace the sensor and/or wire connections with the help of a qualified plumber.

Bosch Error Code A8 Check this : The water temperature sensor is faulty. Item to check : Replace the sensor and/or wire connections with the help of a qualified plumber.

Bosch Error Code A9 Check this : Outlet hot water temperature sensor disconnected or damaged. Item to check : Replace the sensor and/or wire connections with the help of a qualified plumber.

Bosch Error Code AA Check this : No hot water or inconsistent temperatures. Item to check : Turn the power off, turn on the hot water and turn the power back on. If this doesn’t work, check the gas supply pressure with the help of a qualified plumber.

Bosch Error Code AD Check this : Condensing unit flue gases temperature too hot. Item to check : Check flue gas temperature sensor, water inlet temperature sensor, and descale the tankless water heater with the help of a qualified plumber.

Bosch Error Code BB Check this : Flue blockage detected during startup Item to check : Reset error (press and hold on/off button for 3 seconds). If issue persists, Check air openings and exhaust opening for obstructions and reset. Check if flue length is according to manual specification and reset the system to clear error. Check if the air filter is dirty or clogged, replace it if needed. Perform gas and air tuning according to manual, or with the help of a qualified plumber.

Bosch Error Code BC Check this : Fan calibration triggered due to missed ignitions Item to check : Check gas inlet pressure and perform gas and air tuning with the help of a qualified plumber.

Bosch Error Code C1 Check this : Successive fan calibration with similar learned values. Item to check : Check gas inlet pressure and perform gas and air tuning with the help of a qualified plumber.

Bosch Error Code C3 Check this : Little to no air flow meaning that the heater cannot start up. Item to check : Turn the hot water tap on to its full capability and then turn it off. Then turn the system on and off.

Bosch Error Code C5 Check this : Flow sensor does not detect water recirculation. Item to check : Check pump and connections, then check recirculation circuit for any blockage.

Bosch Error Code C6 Check this : Bypass water valve disconnected or damaged. Item to check : Check bypass water valve wire connections, if error continues, Replace the bypass water valve and/or wire connections with the help of a qualified plumber.

Bosch Error Code C7 Check this : Primary fan rotation too low Item to check : Check gas pressure. Low gas pressure may cause the fan to change its speed to meet desired temperature. Possible defective control unit call a qualified plumber to fix the issue.

Bosch Error Code C8 Check this : A faulty fan, only cold water will be able to be used. Item to check : Replace the fan and/or wire connections with the help of a qualified plumber.

Bosch Error Code C9 Check this : Main water valve disconnected or damaged. Item to check : Check main water valve wire connections, if error continues, Replace the main water valve and/or wire connections with the help of a qualified plumber.

Bosch Error Code CA Check this : Barometric pressure sensor damaged. Item to check : Reset error, if problem persists, replace electronic control unit (ECU) with the help of a qualified technician.

Bosch Error Code CE Check this : Water Flow Fault Item to check : Disconnect power supply cord and check wire connections on water valve and the two connectors on the control board. Excessive water pressure/flow, call a qualified plumber to fix the issue.

Bosch Error Code CF Check this : Excessive flue blockage detected Item to check : Excessive flue blockage detected during operation due to excessive pressure on the siphon. Check exhaust pipes and terminals for obstructions and reset the error.

Bosch Error Code E0 Check this : Excessive flue blockage detected during operation due to insufficient combustion air. Item to check : Check air intake and exhaust pipes and terminals for obstructions and reset the error.

Bosch Error Code E1 Check this : Electronic control unit internal error. Item to check : Reset error, if problem persists, replace electronic control unit (ECU) with the help of a qualified technician.

Bosch Error Code E2 Check this : Hot water temperature above 90°C Item to check : Disconnect the appliance and purge hydraulic circuit to remove air, if problem persists, reduce set point temperature to minimise temperature instabilities with the help of a qualified technician.

Bosch Error Code E3 Check this : Cold water temperature sensor fault Item to check : Check connector on wires coming from top of water valve for a secure connection, Sensor may trip if water temperature drops below 2°C. Protect heater from freezing conditions.

Bosch Error Code E4 Check this : Exhaust temperature sensor Item to check : Descale the tankless system, reset error, if problem persists, check sensor resistance and replace the sensor with the help of a qualified technician.

Bosch Error Code E5 Check this : Backflow Temperature Sensor Item to check : Check inlet/outlet vent pipes, check if secondary fan connections are disconnected, check venting specifications are met. Long vent lengths, venting with more than three elbows, blocked vent or combination venting may cause this failure.

Bosch Error Code E7 Check this : Condensing unit flue gases temperature too hot. Item to check : Descale the tankless system, reset error, if problem persists, check sensor resistance and replace the sensor with the help of a qualified technician.

Bosch Error Code E8 Check this : Electronic control unit internal error. Item to check : Reset error, if problem persists, replace electronic control unit (ECU) with the help of a qualified technician.

Bosch Error Code E9 Check this : Error during ionization test Item to check : Error during ionization test. Electronic control unit internal error, replace electronic control unit (ECU) with the help of a qualified technician.

Bosch Error Code EA Check this : Thermal fuse broken Item to check : Replace thermal fuse with the help of a qualified technician.

Bosch Error Code EB Check this : Ignition failure. Item to check : Check gas inlet pressure and perform gas and air tuning with the help of a qualified plumber.

Bosch Error Code EC Check this : Electronic control unit internal error Item to check : Reset error, if problem persists, replace electronic control unit (ECU) with the help of a qualified technician.  

Bosch Error Code EE Check this : Flame lost during operation. Item to check : Check gas inlet pressure and perform gas and air tuning with the help of a qualified plumber.

Bosch Error Code EF Check this : Gas valve modulation solenoid disconnected Item to check : Check gas valve wire connection, if problem persists, replace the gas valve and/or wire connections and or electronic control unit (ECU). For gas valve replacement, perform gas and air tuning with the help of a qualified technician.

Bosch Error Code F2 Check this : Wrong gas connected. Item to check : Wrong gas connected (LPG instead of Natural Gas) for current appliance configuration, check gas type.

Bosch Error Code F7 Check this : Electronic control unit internal error Item to check : Reset error, if problem persists, replace electronic control unit (ECU) with the help of a licensed gas technician TSSA.

  Bosch Error Code FA Check this : Ionization error at standby Item to check : Loose connection to the flame ionization rod. Verify that the thinner wire leading from the control unit is securely connected to the set of electrodeslocated on the lower front of the heat exchanger, flame ionization rod or control unit may be damaged, call a qualified technician to rectify the issue.