Error F0 272

Safety precautions:

- Before doing anything isolate electrical power to the boiler at the boiler isolator or consumer unit. If you are not confident working around electrical equipment, stop and call a Gas Safe engineer.

- Do not attempt to adjust gas controls, burner components, or replace the PCB/HCM yourself. Those tasks require a registered engineer.

- Check warranty paperwork and the installer/manufacturer helpline first — if the boiler is under warranty do not tamper with sealed components.

Initial checks a homeowner can safely do:

1) Note the exact displayed code and any flashing indicator lights; take a photo and time/date for reference.

2) Try a controlled reset: press and hold the reset (or ✔) button for about 8 seconds until the display reboots, or follow the manual reset procedure. Wait and see if the boiler attempts to run and whether the code returns. Do not attempt repeated rapid resets; allow a few minutes between attempts.

3) Check the mains supply and external controls: ensure the boiler is getting power (other appliances or the boiler display active), the room thermostat/programmer is calling for heat, and the gas supply to the house is on. Confirm central heating pressure is in the normal range (typically 1–1.5 bar when cold) but do not top up unless you know the system.

4) Look for obvious signs of trouble: visible water leaks around the boiler, corrosion, burned connectors, or a strong electrical burning smell. If you see any of these, do not power the boiler back on and call an engineer immediately.

Specific diagnostic steps (only if you are competent with basic electrical safety and the boiler is isolated):

1) Isolate electrical supply at the fused spur and confirm the boiler has no power. Remove the outer casing only if you are comfortable and have followed isolation steps.

2) Visually inspect the control box area and the HCM/code plug: check that the HCM (a small plug-in module on many Worcester models) is correctly seated, that the code plug is present and undamaged, and that wiring connectors are fully inserted and not corroded or burnt. Look for signs of water ingress around the PCB or green/white corrosion on pins.

3) If a connector or the HCM looks loose, carefully reseat it (push in firmly) then reassemble, restore power and test. If water or damage is present, do not power up—call an engineer.

4) If reseating does not clear the fault and there are no obvious physical faults, do not attempt component replacement. The control box (PCB) and HCM require diagnostic equipment and safe procedures to replace and to verify ignition and gas circuits afterward.

When to call a professional and what they will do:

- Call a Gas Safe registered engineer if the fault returns after a reset, if the HCM/PCB shows any sign of damage, if you are uncomfortable opening the boiler, or whenever the boiler will not operate. Also call if you find water ingress or burned connectors.

- The engineer will run electronic diagnostics, check software/firmware and code-plug/HCM compatibility, test ignition/flame sensing and the gas valve, inspect sensors and wiring, and, if needed, fit a replacement HCM or control box. They will also test the boiler for safe operation following any parts replacement.

Other important notes:

- Do not repeatedly reset a boiler to bypass a recurring fault — that can mask an unsafe condition and cause further damage.

- If the boiler is under warranty contact Worcester Bosch or your installer first; an authorised engineer should carry out warranty repairs.

- Always use a Gas Safe registered engineer for any work that involves gas or mains electrical connections.