Boiler displays F.83 on start-up, especially after draining or new install

Safety: Allow boiler to cool before bleeding.

• Top up system: Ensure pressure is 1.0–1.5 bar.
• Bleed radiators and boiler: Bleed all radiators and any automatic air vents near the boiler. Bleed the pump if accessible.
• Check NTC contact: Ensure flow and return sensors are firmly attached to the pipes.
• Reset and test: Reset the boiler and run heating, checking that all radiators warm evenly.