Error E.02 – .16

Safety precautions:

1. If you smell gas, evacuate the property immediately, do not operate electrical switches, open windows and call the gas emergency number. Do not attempt any repairs.

2. If you see smoke, burning smell, or visible electrical damage, switch off the mains power at the household consumer unit and call a professional.

3. Do not open the sealed boiler casing or attempt to replace PCB components yourself. Internal work involves live electricity and gas and must be carried out by a Gas Safe engineer.

Initial checks a homeowner can safely do:

1. Note the exact fault code and model details and take a photo of the display. This helps the engineer.

2. Try a single reset: press and hold the boiler reset button for 5–10 seconds (follow the boiler manual if unsure). Wait for the boiler to attempt restart and observe if the code returns. Do not keep repeatedly resetting if the fault returns immediately.

3. Check mains power to the boiler: is the boiler display on? Check the fused spur or switch for the boiler and the household fuse box to ensure the circuit hasn’t tripped.

4. Check gas supply: confirm other gas appliances (hob) light to rule out a gas supply shut-off. If gas is off, contact your supplier or Gas Safe engineer.

5. Check system water pressure: look at the pressure gauge on the boiler. Aim for 1–1.5 bar for normal operation. If pressure is very low (under 0.5 bar) top up the system using the filling loop following the boiler manual. If pressure keeps dropping, that indicates a leak or other issue and you should stop and call an engineer.

6. Do a visible external inspection only: with the boiler switched off at the mains, look for signs of external water leaks, corrosion on pipework, or obvious burn marks on the case. Do not remove covers or touch internal components.

Specific diagnostic and next steps (non-intrusive):

1. If the fault cleared after one reset and the boiler operates normally for a while, monitor the system closely. If E.02-.16 returns, stop using the boiler and arrange a professional visit.

2. If the fault persists after reset and the initial checks (power, gas, pressure) are normal, isolate the boiler by switching it off at the mains and leave it off until a Gas Safe engineer attends.

3. When you call the engineer, tell them the exact error code (E.02 – .16), the boiler model (Baxi 200 / 400 Combi), and the checks you have already completed (reset attempted, pressure reading, gas supply check, visible leak or damage). This speeds diagnosis.

4. The engineer will perform electrical/communication checks, inspect and test connectors and wiring to the CSU/PCB, check for water ingress or burnt components and may replace the CSU or PCB if faulty. They will also check associated modules such as the gas/air unit and fan communication if needed.

When to call a professional and final notes:

1. Because E.02 – .16 is logged as a permanent/communication timeout fault and often points to PCB or CSU failure, you should arrange a Gas Safe registered engineer — do not attempt internal repairs yourself.

2. Do not repeatedly reset the boiler if the fault returns; repeated resets can stress components and may hide progressive damage.

3. If the boiler is under warranty or a service contract, have your policy details ready for the engineer. Provide photographs and a clear timeline of what happened to help with diagnosis.

If you need immediate assistance because of a gas smell or electrical danger, follow emergency advice above and contact the emergency services or gas emergency number before arranging repairs.