Error CE 266

Safety precautions:

- If you smell gas, leave the building immediately and call your gas emergency number. Do not operate electrical switches.

- If the boiler casing is hot, or you see leaking water, switch the boiler off at the isolator and the mains and call a Gas Safe engineer.

- Only perform non-invasive checks (visual, pressure check, bleed radiators). Do not open the boiler or attempt electrical/gas repairs unless you are a qualified engineer.

Initial checks a homeowner can do:

1) Check the boiler display and note the exact fault code (CE 266) and any other codes or flashing indicators. Take a photo for the engineer.

2) Try a single reset: press and hold the boiler reset button for about 5 seconds, then wait a few minutes to see if the fault clears and the boiler attempts to start. Do not repeatedly reset more than 2–3 times.

3) Check the system pressure on the boiler gauge. Many Worcester boilers require around 1–1.5 bar when cold. If pressure is very low (below ~0.5 bar or the manufacturer minimum), repressurise using the filling loop following the boiler handbook. Only do this if you are comfortable and know how; close the filling loop when pressure is correct.

4) Check that any external pump isolation valves (usually near the pump) are fully open. If the pump has a switched isolation lever, ensure it is in the run position.

5) Bleed a few radiators to remove trapped air and then re-check system pressure. Airlocks can prevent the pump from developing flow.

6) With the boiler powered on and calling for heat, stand close (but not touching) to listen for the pump. You may hear a hum or gentle running. Note if there is silence, a loud grinding noise, or repeated clicking.

Specific diagnostic steps and possible next actions:

1) If a low pressure condition fixed the fault: after repressurising and bleeding radiators, reset the boiler. If CE 266 clears and the system runs, monitor pressure and heating performance. If the fault returns, call an engineer because a persistent leak or pump fault may be present.

2) If the pump isolation valves were closed and opening them clears the fault: monitor the system. If valves were closed accidentally, ensure they remain open and get a pro if you suspect the pump has been allowed to run dry.

3) If you can hear the pump trying to run but there is no flow and you are competent with safe, isolated checks only: you can check for obvious visible issues (loose wires, corrosion on connectors) but do not remove the pump cover or work on wiring unless qualified. Do not pour water or apply power leads.

4) If the pump is silent (no hum) when the boiler is calling for heat, the cause may be an electrical fault, control board output, or pump failure. These require a Gas Safe engineer to test voltages, motor continuity and control signals.

5) If the pump is noisy or appears to be seizing (grinding/rattling), stop using the boiler and call an engineer. A seized pump can be damaged further if driven electrically.

6) If you suspect an airlock remains after bleeding, try systematically bleeding radiators from the highest to lowest points, then re-check pressure. Do not open or tamper with pipework internal to the boiler.

7) Document everything (times, actions taken, readings, photos of the display and any valves). This information will help the service engineer diagnose more quickly.

When to call a professional:

- If the fault does not clear after the simple steps above (reset, correct pressure, bleed radiators, open isolation valves).

- If the pump is loud, noisy, seized or completely silent when it should be running.

- If you find loose wiring, water inside electrical compartments, or cannot safely access the filling loop/isolation valves.

- If there are multiple fault codes or repeated lockouts.

A Gas Safe qualified engineer should be called to perform in-depth electrical checks, pump removal/replacement, and any repairs inside the boiler or to gas components. Provide the engineer with the CE 266 code, your observations and the steps you have already tried.