Boiler shows E119, pressure gauge near zero, boiler will not fire

Safety first: Allow the boiler to cool before topping up pressure.

User checks:

• Locate the filling loop (usually a silver braided hose) and slowly open the valves to raise pressure to 1.0–1.5 bar, then close both valves.
• Reset the boiler and check for normal operation.
• Monitor pressure over several days; if it drops again, a leak or expansion issue is likely.

Engineer checks:

• Inspect the system for leaks, including the pressure relief valve discharge pipe outside.
• Check the expansion vessel pre-charge and recharge or replace if the diaphragm has failed.
• Test the pressure sensor and replace if it gives incorrect readings.

Do not repeatedly top up a system that is losing pressure; find and fix the underlying cause.