Boiler shows 107, no heating or hot water, pressure gauge may read low

Safety: Only top up the system when the boiler is cool. Do not over-pressurise.

• Check pressure: Look at the pressure gauge. If below 0.8–1.0 bar, you must repressurise.
• Top up via filling loop: Locate the Ariston filling loop (flexible hose or built-in valves). Open the valves slowly until the gauge reaches 1.2–1.5 bar, then close both valves fully. Never leave the filling loop open.
• Bleed radiators: After topping up, bleed radiators to remove air, then recheck pressure and top up again if needed.
• Check for leaks: Inspect all visible pipework, radiator valves, and the boiler underside for signs of water. Any leak must be repaired before repeated topping up, as fresh water accelerates corrosion.
• Expansion vessel check: If pressure rises above 3 bar when hot and drops to zero when cold, the expansion vessel may have lost charge or failed. This requires a professional to recharge or replace.
• Reset boiler: Once stable pressure is restored, reset the boiler. If 107 returns frequently, call an engineer to investigate hidden leaks and vessel condition.