Ideal Logic System IE fault FU
Differential greater than 50°C
Gas boilerWhat it means
Flow/return temperature differential exceeds 50°C.
Likely causes
- Isolation valves closed
- Pump fault
- Radiator valves closed
- System blockages
Where to start
- Check isolation valves are open
- Check pump
- Check rad valves open
The full answer, free
- 3 more checks in order
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 54), right under the answer
Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.
From the Ideal manual for the Logic System IE. Check the model on the data plate before you order parts.
Other Ideal Logic System IE fault codes
- F02Flame loss
- F04Flow thermistor fault
- F05Return thermistor fault
- F0DLow water flow / low water pressure
- F0UFlow/return differential greater than 50°C
- F10Spark generator fault
- F12Pump rotor blocked
- F13Pump fault
- F15Pump fault
- F16Gas valve fault
- F17Pump fault
- F2Flame loss
- F3Fan fault
- F4Control/no flow thermistor fault
- F5Return thermistor fault
- F6Outside sensor fault
- F8PCB unconfigured/faulty or gas valve short circuit
- F9PCB unconfigured/faulty or gas valve short circuit
- FDNo water flow
- FNFlame loss
- L02Ignition lockout after 5 attempts
- L04Flow thermistor fault
- L05Return thermistor fault
- L06False flame lockout / flame on before gas valve on