Fault codes / Truma AquaGo / 2
Truma AquaGo code 2
What it means: Overtemperature switch (EOS or BOS) open.
What to check
Let it cool, check water flow and scale, then test the switch. Find why it overheated.
Learn the system
Practice it on a service call
Guided diagnosis
Other Truma AquaGo codes
- Truma AquaGo code 1 No flame after 3 tries
- Truma AquaGo code 3 Exhaust pressure switch
- Truma AquaGo code 4 Water over 185 F (WOS)
- Truma AquaGo code 5 Flame seen at the wrong time
- Truma AquaGo code 6 Safety circuit switch open
- Truma AquaGo code 7 Control board memory fault
- Truma AquaGo code 9 Outlet sensor (WOT) fault
- Truma AquaGo codes 10 and 11 Safety circuit or watchdog fault
- Truma AquaGo codes 12 and 16 Internal control fault
- Truma AquaGo code 13 Shut-off valve current over 1000 mA (short)
- Truma AquaGo code 20 Inlet sensor (WIT) fault, or inlet below 14 F
- Truma AquaGo code 21 Circulation sensor (WCT) fault
- Truma AquaGo code 22 Gas valve modulator fault
- Truma AquaGo code 23 Voltage over 16.4 V
- Truma AquaGo code 24 Voltage under 10 V
- Truma AquaGo code 25 Flue fan current fault
- Truma AquaGo code 26 Circulation pump current fault
- Truma AquaGo code 27 Pump running dry
- Truma AquaGo code 28 Low gas pressure
- Truma AquaGo code 29 Too much hot water demand
- Truma AquaGo code 30 Freeze risk below about 27 F
- Truma AquaGo code 31 Decalcification finished
- Truma AquaGo codes 32 and 33 Antifreeze kit current fault
Full field guide: Truma AquaGo tankless water heater
Codes come from the maker manuals and public service sheets. Your model's own chart always wins, and LP and 120 volt work belongs to a qualified technician.