Error E10

Safety precautions:

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

- Before opening any part of the boiler or touching internal wiring, isolate electrical power at the fused spur or consumer unit and isolate the gas if instructed by a qualified engineer.

- If you are not comfortable with basic electrical checks or working near gas appliances, stop and call a Gas Safe registered engineer.

Initial homeowner checks (no internal access required):

1. Note the exact error code and any other codes or messages on the boiler display. Record when the fault started and any events (power cuts, storms, recent work on the system).

2. Check the boiler pressure on the gauge/display. Some Baxi fault lists show E10 for outdoor sensor but other sources associate E10 with pressure issues on different models. If pressure is below about 1.0 bar, topping up to the normal working pressure (typically 1.0–1.5 bar when cold) may allow the boiler to resume — follow your boiler user manual for filling the system via the filling loop. If unsure, do not attempt and call a professional.

3. Try a basic reset: use the boiler reset button or the control panel reset option. Wait a few minutes to see if the boiler clears the error and starts normally. If it locks out again with the same code, continue with checks.

4. Visually inspect the outdoor sensor and its mounting point (if accessible): look for physical damage, water ingress, corrosion, crushed cable, or rodent damage. Check that the sensor is still attached and the cable runs back toward the boiler.

Simple diagnostic steps (only if comfortable and safe to do):

5. Follow the user manual guidance on access panels: with mains power isolated, open the boiler service panel only if you are competent. Locate the outdoor sensor connection (refer to the wiring diagram in the manual). Check that the connector is seated and free of corrosion. Re-seat the connector if it appears loose.

6. If you have a multimeter and basic skills: with the sensor disconnected from the boiler, measure the sensor resistance. An NTC sensor will change resistance as temperature changes (resistance falls as it warms). You can check for an open-circuit (infinite/very high resistance) or a short (near 0 ohms). Do not work on live circuits; measure only with power off. If you are unsure what the expected values are, note that the key result is whether the resistance changes with temperature (warm with your hand or a warm cloth vs ambient). If there is no change, the sensor is likely faulty.

7. Check wiring continuity between the sensor plug and the boiler terminal if you suspect cable damage. Repair or replacement of wiring should be done by a qualified engineer.

8. If the sensor appears corroded, water-damaged, or physically broken, replacement of the outdoor probe is usually the fix. Use the correct Baxi OEM or compatible replacement part for your model.

When to call a professional:

- If the error persists after a reset and basic visual checks.

- If you find an open or shorted sensor, damaged cable, corroded connectors, or if internal PCB faults are suspected.

- If you are not comfortable isolating power or using a multimeter, or you need the sensor replaced.

What to tell the engineer / prepare before the visit:

- Model and serial number of the boiler, the exact error code (E10) and any other codes shown, what checks you have already done (reset, pressure level, visual inspection), whether the sensor cable or sensor is damaged, and when the problem began.

- Take a photo of the sensor location and the boiler display if possible — that helps diagnostics.

Final notes:

- Do not attempt to repair gas valves, PCB components, or live wiring yourself. Replacing sensors and repairing wiring is best done by a Gas Safe registered engineer who can also confirm there are no related safety issues.

- If repeated low pressure or leak issues accompany the fault, mention this to the engineer as it may indicate a separate system problem.