Error 328

Safety precautions:

- If you smell gas or suspect a carbon monoxide leak, evacuate the property, call the gas emergency number and do not use the boiler. Do not attempt internal repairs.

- Before touching any electrical parts, isolate the boiler at the fused spur or consumer unit. If you are not confident working with mains electricity do not open covers or remove wiring. Contact a qualified electrician/engineer.

- Do not repeatedly press reset more than once or twice. Repeated resets can mask an ongoing electrical problem and risk damage.

Initial homeowner checks you can do safely:

1. Note and record the exact error code and any secondary/blocking code shown on the display (write date/time and any other symbols). This helps the engineer.

2. Check the house consumer unit (fuse box) for any tripped MCBs or RCDs and reset them if safe to do so. Check the boiler fused spur fuse (if accessible) and replace a blown fuse with the correct rating.

3. Check whether other electrical appliances or the whole neighbourhood are affected — is there a recent power cut, flickering lights, or other equipment behaving oddly? If the supply is unstable across the property, contact your electricity network operator (DNO) or supplier.

4. If you have an external backup supply, solar inverter, battery or generator that could alter frequency, switch those systems off temporarily (following their safe shutdown procedures) and retest the boiler.

5. Attempt a single reset of the boiler using the manufacturer's reset procedure. After reset, allow 5–10 minutes to see if the error returns. If it clears and stays clear, monitor the boiler closely.

Diagnostic steps and information for an engineer (and what a homeowner should communicate):

- If the error returns after a single reset, do not continue to reset. Record how often it happens and any patterns (after storms, after mains switching, at certain times of day, after using a generator, etc.).

- If you are competent and own appropriate test equipment: an electrician can measure incoming mains voltage and frequency at the boiler supply. Expected values are nominal voltage around 230 V AC and frequency around 50 Hz (small tolerances apply). Significant deviation or instability indicates a supply issue. If you are not trained, do not attempt these measurements yourself.

- If mains voltage and frequency are normal and stable, the fault is likely inside the boiler (a failing internal power supply, mains filter, or control PCB). The control board may log the cause; an engineer will inspect the PCB for burnt components, loose connections or water damage and may replace the relevant module.

Recommended actions and when to call a professional:

- If the simple homeowner checks above do not resolve the fault, contact a qualified electrician to test the incoming supply and the boiler’s fused spur and isolation. If the electrician finds the mains supply unstable, they will advise contacting the distribution network operator or your energy supplier.

- Contact a Gas Safe registered heating engineer to diagnose and repair internal boiler faults (control PCB, internal power module, wiring inside the boiler). Give them the recorded error code (328), any blocking codes, a history of resets and any notes about recent power problems or external generation equipment.

- Do not attempt to repair or replace control electronics, internal wiring, or gas-related components yourself. Only a Gas Safe engineer should open and work on the boiler’s gas and combustion systems.

What information to have ready for the engineer or electrician:

- Exact error code and any display messages, time and frequency of occurrence, results of any reset attempt, evidence of power instability (flickering lights, other appliances affected), presence of solar/battery/generator equipment, and the boiler model and serial number.

Final safety reminder:

- Error 328 relates to mains/electrical supply and potentially to the boiler’s control electronics; untreated, it can lead to further failures. Because the fault involves mains power and internal electronics, limit yourself to the safe checks above and call a qualified electrician and a Gas Safe registered engineer to complete diagnostics and repairs.