Error H.02 – .02

Safety precautions:

- If you smell gas or suspect a gas leak, immediately evacuate the property and call the gas emergency number. Do not operate electrical switches or the boiler.

- If you are unsure or uncomfortable working near the boiler controls or casing, stop and call a qualified engineer. Do not attempt internal PCB repairs.

- Isolate power to the boiler before removing any panels or inspecting internal wiring. Use the isolator switch or turn off the fuse at the consumer unit.

Initial homeowner checks you can safely do:

1. Record the exact error code and any additional lights or messages on the display and note when it first appeared.

2. Try a simple reset: press and hold the boiler reset button for 3–5 seconds (or follow the manufacturer reset instructions). Wait for the boiler to attempt restart and observe whether the H.02 .02 clears.

3. Power-cycle the boiler: switch the boiler off at the isolator or fuse, wait 30–60 seconds, then switch back on and check for the error returning.

4. Check for recent work or changes: if the PCB or control unit was recently replaced or the boiler was serviced, inform the engineer — missing configuration often follows a component replacement.

5. If you have an external controller, thermostat, smart relay or HMI panel fitted, disconnect or turn off those devices temporarily and retry a reset in case external devices are affecting configuration/communication.

Specific diagnostic and next-step actions (only if you are competent with basic electrical isolation and visual checks):

1. With power isolated and the front panel removed, perform a visual inspection for loose connectors or obvious damage to the PCB or display cable. Do not probe or touch components unless you are trained. Re-seat any multi-pin connectors that are clearly loose (only after isolating power).

2. Look for a separate programming/PU module, memory plug, or configuration switches on the PCB (C1/C2 may refer to configuration input pins or settings). If the module has become dislodged, a qualified engineer can reseat or replace it—do not force-fit components yourself.

3. If the boiler returns to normal after reset but the H.02 .02 reappears intermittently, suspect a corrupted configuration, failing PCB, or intermittent connector/communication fault. Note the frequency and any related events (power cuts, recent service, lightning, etc.).

4. If the error remains after resets and visual checks, do not continue attempting repeated resets—this may mask an underlying fault and delay proper repair.

When to call a professional:

- If the simple reset and power-cycle do not clear the fault, or if the error returns repeatedly, you should contact a Gas Safe registered heating engineer or Baxi service technician. The fix typically requires reprogramming the PCB parameters (C1/C2), fitting/configuring the correct programming unit, or replacing a faulty PCB or connector — tasks that require the correct diagnostic tools and manufacturer settings.

- Always call an engineer immediately if you smell gas, see water leaks, or if other fault codes appear alongside H.02 .02.

Summary: try reset and power-cycle, do only safe visual checks and connector reseating with power isolated, but expect to need a qualified engineer to configure the PCB or replace faulty components if the fault persists.