Error C7 217

Safety precautions:

- Do not open sealed boiler panels or touch internal components. Only qualified Gas Safe engineers should access live wiring or the fan assembly.

- If you smell gas, turn off the gas at the meter, get everyone out, and call the national gas emergency number immediately. Do not operate electrical switches.

- Turn the boiler off at the programmer and at the boiler's isolator switch before carrying out any visual external checks.

Initial checks a homeowner can safely do:

1) Power cycle/reset: Switch off the boiler at the isolator or fuse spur, wait 30 seconds, and switch it back on. Note the displayed fault and whether it clears or returns.

2) Observe the boiler during a start attempt: When you request heat/hot water, stand close and listen for the fan starting during the pre-ignition sequence. If you hear nothing or a struggling/irregular noise, it supports a fan fault.

3) Check the external flue and air intake: Inspect the outside flue terminal and any vents for obvious blockages (birds nests, leaves, debris, snow/ice). Remove external obstructions safely from outside the house only. Do not force anything into the flue.

4) Check system pressure: Confirm boiler water pressure is within the recommended range (typically around 1.0–1.5 bar). Low pressure can cause other faults; repressurise only if you know how to do so safely according to the manual.

5) Environmental checks in cold weather: If temperatures are below freezing, ensure the condensate pipe is not frozen or blocked. A blocked condensate can sometimes cause start-up problems.

Diagnostic and next-step actions (homeowner + engineer responsibilities):

- If the basic checks above clear the fault, monitor the boiler. If C7 returns or is intermittent, stop using the boiler and contact a Gas Safe engineer. Record when the fault occurs and any symptoms (no fan noise, humming, flashing patterns).

- If there are visibly damaged external wiring or connectors outside the sealed unit (for example a badly chafed external cable), isolate the boiler and report this to the engineer. Do not attempt to repair wiring yourself.

- When you call an engineer, provide: boiler model (Worcester Bosch GB162), exact error code (C7 217), whether the fan makes a noise on start, whether the fault is constant or intermittent, recent service history, and photos of the display and external flue if possible.

What the Gas Safe engineer will do (for your awareness):

- Perform safe live tests and measure the voltage/signal to the fan and PCB communication.

- Inspect and, if necessary, remove and clean the fan assembly and check for mechanical seizure or obstruction.

- Replace the fan motor or fan assembly if faulty, or repair/replace the PCB if the fan signal is not being read correctly.

- Check flue integrity, seals, and ensure no soot or restriction inside the flue path.

Important final notes:

- Do not attempt to access or repair internal fan assemblies, the PCB, or test mains voltages unless you are a qualified Gas Safe engineer. These are live, safety-critical tasks.

- If the fault persists, turn the boiler off and arrange an engineer visit. Continued attempts to force the boiler to run can cause further damage or create unsafe conditions.

- Regular annual servicing by a Gas Safe engineer helps detect wear before faults develop and is recommended to reduce the chance of C7 and related faults.