System pressure has dropped too low for the boiler to run safely.
Most common on: Baxi 600, Baxi 800, EcoBlue, Platinum+, Duo-tec
E119 means the water pressure in the sealed heating system has fallen below the minimum the boiler needs, typically around 0.5 bar. The boiler shows the code and stops rather than running with too little water in the system.
Low pressure is common and often simple to fix by topping up with the filling loop, but pressure that keeps dropping points to a leak or a failed expansion vessel rather than normal gradual loss.
Check the pressure gauge or display reading. If it is below about 1 bar, the system needs topping up.
Open the filling loop slowly until the gauge reads about 1.0–1.5 bar (cold), then close it fully and reset the boiler.
If the pressure keeps falling, there is a leak or an expansion vessel fault — book an engineer rather than topping up repeatedly.
A hidden leak or a failed expansion vessel needs a heating engineer to find and fix — repeatedly re-pressurising a leaking system can cause further damage.
Work on the gas side of a boiler must be carried out by a Gas Safe registered engineer. The checks above are limited to safe, non-invasive things a homeowner can look at (pressure, resets, the gas supply) — if in doubt, stop and call an engineer.
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System pressure has dropped too low for the boiler to run safely. E119 means the water pressure in the sealed heating system has fallen below the minimum the boiler needs, typically around 0.5 bar. The boiler shows the code and stops rather than running with too little water in the system.
Often yes — this one is frequently resolved by a homeowner. Check the pressure gauge or display reading. If it is below about 1 bar, the system needs topping up. If it keeps coming back, book a Gas Safe registered engineer.
A recurring E119 means the underlying cause has not been fixed — most often gradual pressure loss over time (normal — needs occasional topping up). Resetting repeatedly will not solve it; get the boiler diagnosed properly.
Overheat — primary circuit too hot
Circulation fault
Gas supply fault / ignition lockout
See all Baxi fault codes.