Error E119

Safety precautions:

- Before doing anything switch the boiler off at the programmer/thermostat and isolate electrical supply if instructed in your manual. Allow the boiler to cool to avoid scalding.

- Never open or attempt to service gas components or internal boiler parts unless you are a qualified engineer. If you smell gas, leave the property and call the gas emergency number immediately.

- Use caution around valves and pipework; wear gloves and protect floors from drips.

Initial checks a homeowner can do:

1. Check the pressure gauge on the front of the boiler. If it reads below about 1.0 bar (often under the green area), low pressure is likely the cause of E119.

2. Inspect visible pipework, radiators and underneath the boiler for signs of leaks (wet spots, corrosion, puddles). Check radiator bleed points for weepage if recently bled.

3. Recall whether you have recently bled radiators or had plumbing work done; that often causes pressure loss.

4. In very cold weather check the condensate pipe (usually a plastic pipe running outside or to a drain) for freezing. A frozen condensate pipe can cause faults; don’t pour boiling water on it—use warm water to thaw carefully.

5. If the gauge reads normal but the code persists, consider that the pressure sensor or wiring could be faulty; do not attempt internal electrical repairs.

How to repressurise (if you are confident to do so):

1. Turn the boiler off and allow it to cool. Locate the filling loop beneath the boiler or a dedicated filling valve. The filling loop is usually a short flexible metal hose or two isolation taps/valves beneath the unit. Some boilers have a green lever or an integrated easy-fill valve.

2. If your filling loop has removable caps, remove them. Make sure the loop is firmly attached and the valves are closed initially.

3. Slowly open the mains inlet valve first (usually one of the two valves) and then open the second valve slowly until you hear water flow into the system. Watch the pressure gauge closely as it rises.

4. Stop when the pressure reaches about 1.0–1.5 bar (or the green zone marked on the gauge). Do not over-pressurise the system (avoid exceeding about 2.0–2.5 bar). Close both valves tightly and replace any caps.

5. Turn the boiler back on and reset the fault code using the boiler reset button or by cycling power according to your manual. Check that the boiler fires and that pressure stabilises; it may drop slightly when the boiler fires, so aim for the middle of the recommended range when cold.

If repressurising does not clear the fault or pressure immediately falls again:

- Do not repeatedly top up the system as a long-term fix. A persistent fall in pressure usually indicates a leak or a failing component (pressure relief valve, expansion vessel, or internal leak).

- Re-check all radiators, pipework, and valves for leaks. Examine the area under the boiler and any visible joints.

- If you suspect the expansion vessel (symptoms include pressure rising excessively on heating or rapid drops), or the pressure relief valve is dripping, stop and call a qualified engineer.

- If the condensate pipe is frozen or blocked, thaw it and then reset the boiler; if the pipe is blocked internally you may need professional help.

- If the pressure gauge reads fine but the E119 code remains, the pressure sensor, wiring or PCB may be at fault — this requires a qualified engineer to diagnose and repair.

When to call a professional:

- If you find any leak, see water dripping from the boiler or fittings, or pressure continues to fall after repressurising.

- If you cannot locate or operate the filling loop, or you are not confident to repressurise safely.

- If the condensate pipe is frozen and you cannot safely clear it, or if you suspect the expansion vessel, pressure relief valve, or electronic sensors/PCB are faulty.

- For any gas, combustion or internal boiler work. Always use a Gas Safe registered engineer (UK) or your country’s qualified heating engineer for repairs that involve gas, internal boiler components, or when in doubt.

Following these steps will clear many E119 low-pressure faults, but persistent problems require professional inspection to find and fix leaks or faulty components rather than repeatedly topping up the system.