Fault code 1P4 or 108
Fault code 1P4 or 108 indicates low water pressure within the system, which is a simple fix that all owners can perform themselves.
What does Fault Code 1P4 / 108 mean?
- 1P4 (or F1P4) is sometimes displayed as Fault Code 108.
- It indicates that the water pressure in your boiler has dropped below the safe operating level.
- Most boilers require the pressure to be around 1.0 to 1.5 bar when cold.
How to Fix Fault Code 1P4 / 108 (Low Water Pressure):
Check the Pressure Gauge
- Look at the boiler’s pressure gauge (usually at the front or underneath the boiler).
- If it reads below 1.0 bar, you need to top it up.
Re-Pressurise the Boiler
- Locate the filling loop (a silver flexible braided hose beneath the boiler with small tap handles).
- Slowly open the valves to allow water into the system.
- Keep an eye on the pressure gauge and close the valves when it reaches 1.2 - 1.5 bar.
Reset the Boiler
- After repressurising, reset the boiler using the reset button on the control panel.
- The fault code should clear if pressure is restored.
Check for Leaks
- If pressure keeps dropping, check for visible leaks on radiators, pipes, or boiler components.
- Leaks must be repaired before repressurising again.
