Error 208 0

Safety precautions:

1) If you smell gas, evacuate the property immediately and call your gas emergency number. Do not operate electrical switches near the boiler or try to relight anything.

2) Do not attempt to open the boiler casing, work on the gas pipework, or manipulate the flue. Those tasks must be carried out by a Gas Safe registered engineer.

3) Before touching any electrical wiring or terminals, isolate the boiler supply at the fused spur or external isolator and wait a minute. Only inspect visible wiring if you are confident and the power is off.

Initial homeowner checks (simple, safe actions):

1) Confirm the display shows 208 (chimney sweep) and note any other codes or lights. Take a clear photo of the display for later reference.

2) Ask household members or a visiting engineer whether a sweep or service was recently carried out. If yes, the boiler may have been left in sweep mode intentionally.

3) Press the boiler reset button once and wait 30–60 seconds to see if the display clears and normal operation returns. Do not press reset repeatedly in quick succession.

4) Power cycle the boiler: switch the boiler off at the boiler isolator or fused spur, wait 30 seconds, then switch back on. Check if the code clears.

5) Check the heating controller/room thermostat/programmer to ensure there is a demand for heating or hot water. If the controller is not calling, the boiler may remain idle despite leaving sweep mode.

6) Check system water pressure on the boiler gauge. Low pressure can cause other blocking faults; top up the system only if you know how and it is safe to do so (follow the boiler manual). Low pressure alone does not normally cause a 208 code but is worth confirming.

Specific diagnostic and (safe) fix steps you can try:

1) Locate the boiler’s service mode or service/sweep switch (consult the boiler user manual for the exact location and instructions). If you can identify a service/sweep selector set to the service position, move it back to the normal position and observe whether the boiler returns to normal operation.

2) If your boiler has an external service/sweep terminal (often used by engineers), check for any temporary links or external controls that may be closing that circuit. With the boiler power OFF, visually inspect for an obvious link or wire secured across a labeled pair of terminals. Do not cut or disconnect gas-related wiring. If you see a removable link and it is clearly a temporary fitted link, you can remove it and then power the boiler back on to test.

3) If the boiler still reports 208 after the above, note any additional codes or unusual noises and re-photograph the control panel. If the display shows only 208 and nothing else and you have exhausted safe resets and service-switch checks, it is likely a stuck input or internal control issue.

When to call a professional and what to tell them:

1) Call a Gas Safe registered engineer if: the code does not clear after reset and power cycle; you cannot find or change a service/sweep switch; there are other fault codes; there is a gas smell or water leak; or you are not confident performing the safe checks above.

2) When you contact the engineer, give them the exact boiler model, the displayed code (208 0), any other codes or LED behaviour, what you have already tried (reset, power cycle, check of service mode), and send the photo of the display and any visible wiring or labels. This speeds diagnosis.

3) Ask the engineer to check the external service input, service mode switch, wiring into the PCB, and to run the boiler through normal modes. Any replacement of control modules, wiring repair, flue inspection or gas work must be done by a qualified Gas Safe engineer.

Final notes:

- Error 208 is typically a non-dangerous service mode, but if it prevents heating or hot water and you need the system restored, arrange a Gas Safe visit.

- Do not attempt internal repairs, flue cleaning, or gas valve work yourself. Keep records and photos of the fault and any steps you took before the engineer arrives.