Water Heater
Bosch Water Heater error codes
16 codes across 1 model family. Start with your model number, because Bosch reuses the same numbers for different faults on different boards.
Find your model family
The model number is on the data plate, usually on the side or back of the unit or behind the service panel. It usually starts with the letters or numbers in the name below.
Therm 250SX, GWH 635ES and 2400E gas tankless
Bosch Therm 250SX, GWH 635ES and 2400E gas tankless codes
16 codes
Condensing gas tankless platform with a condensing heat exchanger, an induction fan and a flue gas limiter. Four of its codes, A2, A7, A9 and C1, mean something completely different on the Greentherm T9000 platform, and the gas pressure ranges published for it differ from the T9000 ranges, so the code has to be read against the model family rather than as a Bosch code.
Open the Therm 250SX, GWH 635ES and 2400E gas tankless code list →