Error E10

Safety precautions:

1. If you smell gas, evacuate the property immediately and call the emergency gas number. Do not operate electrical switches or the boiler.

2. Before doing any checks, switch the boiler off at the isolator and, if you can safely access it, switch off the corresponding breaker/fuse in the consumer unit.

3. Do not open the boiler casing or touch internal components unless you are a qualified engineer. Internal PCB work, mains-voltage checks and gas checks must be carried out by a Gas Safe registered engineer.

Initial homeowner checks (safe, simple steps you can do):

1. Record the exact error code and circumstances (when it appeared, after a power outage, after working on the heating, etc.). This helps the engineer diagnose the fault.

2. Try a normal reset: press the boiler reset button and observe whether the fault clears. If it clears but returns, note how and when it reappears.

3. Power-cycle the boiler: switch off at the isolator or breaker, wait 5–10 minutes, then switch back on and re-check the display. This can clear transient electronic faults.

4. Check the household consumer unit and fuses: ensure the boiler circuit has not tripped and that the isolator fuse is intact.

5. Visually inspect the boiler fascia and external case for signs of water ingress, corrosion, burn marks, a strong burnt smell, or physical damage. Also check for recent plumbing leaks near the boiler that might have affected electronics.

6. Ensure the mains supply to the property is stable (if other appliances show power issues, report this to an electrician); low or unstable mains can cause control-box errors.

Further diagnostic information to gather for an engineer (do not attempt internal repairs yourself):

1. Note any accompanying codes or symptoms: loss of display communication, intermittent operation, whether hot water or heating is affected, whether the fan runs, or whether other sensor codes are present.

2. If you are comfortable and it can be done without opening the boiler, check that any external control leads (like room stat, programmer) and visible plug-in leads are secure.

3. Make a note of when the fault first happened and whether anything changed recently (power cuts, service, plumbing work).

What a qualified engineer will check and do (summary of the professional diagnostic/fix steps):

1. Perform full electrical safety checks: measure mains voltage (check it is close to 230 V and within tolerance), check polarity, earth continuity and insulation where required.

2. Access the boiler and inspect the fascia-to-control-board connection and multi-pin connectors for corrosion, loose pins or damaged cables; re-seat connectors if required.

3. Run the boiler's diagnostic and calibration routines and check fault memory to understand whether the control box, sensors or communication lines triggered the error.

4. Check related components that can cause control-box errors: flow and return thermistors, pressure sensor, fan, gas valve wiring, and the fascia/display PCB for faults or damage.

5. If the control PCB is confirmed faulty or intermittent and cannot be repaired, replace the control box/fascia PCB with manufacturer-approved parts, following the boiler service manual and safety procedures. After replacement the engineer will recheck gas rate/combustion if any gas-side work is needed, and confirm correct operation.

6. Clear the fault code and run the boiler through several operational cycles to ensure the fault is resolved and does not recur.

When to call a professional and final notes:

1. If the E10 code persists after a safe reset and basic external checks, arrange for a Gas Safe registered engineer to attend. Most E10 situations require trained diagnostic testing and likely replacement of the control PCB or repair of internal connections.

2. Do not attempt internal PCB replacement, live electrical testing, or gas valve work yourself. These are hazardous and legally restricted to qualified personnel.

3. Provide the engineer with the exact error code, any accompanying codes, and your notes about when and how the fault occurs to speed up diagnosis.

If you want, tell me whether the code appears immediately at power-up, after running the boiler, or intermittently, and any other codes or symptoms you see; I can suggest which checks are most relevant to your situation.