Error E128

Safety first:

- If you smell gas, leave the property immediately, avoid using electrical switches or phones inside, and call the gas emergency number. Do not attempt any repairs.

- Turn off the boiler at the control panel and isolate electrical supply at the wall before carrying out visual checks. Work only in well-ventilated areas.

- Do not attempt to dismantle gas, burner, ignition, flame-sensing or flue components. Those tasks require a Gas Safe engineer.

Initial homeowner checks you can do:

1) Note the exact code and any display/LED behavior. Try a simple reset first: locate the boiler reset button or power button. On many Baxi models press and hold the reset/power button for 3–5 seconds or switch the boiler off at the control, turn off the mains, wait 30 seconds, then turn mains and boiler back on. Consult your manual for the exact reset method for your GA model.

2) Check other gas appliances in the house (hob, gas fire). If they are not working either, suspect a gas supply issue and contact your gas supplier.

3) Check the external condensate pipe (usually a small plastic pipe that drains from the boiler to outside). In freezing weather this can ice up and cause flame/ignition faults. If you find the pipe frozen, warm the exposed section with warm (not boiling) water, a hot water bottle or a warm pack until the ice clears. Do not use boiling water or open flames. After thawing, reset the boiler.

4) Look outside for obvious flue or air intake blockages (bird nests, leaves, snow). Do not put your head over the flue or try to remove deep blockages yourself — just clear any obvious external debris safely.

5) Check boiler pressure on the gauge. Low system pressure can cause faults on some boilers; top up to the manufacturer’s recommended pressure if it is low and you are comfortable doing so (follow manual instructions). If pressure repeatedly drops, call an engineer.

If the fault clears after the checks:

- Monitor the boiler. If E128 is a one-off after freezing or a transient gas supply interruption, it may not recur. If it returns, stop further DIY and contact a professional.

When to call a professional (and why):

- If reset does not clear the fault, or the boiler shows E128 repeatedly.

- If other gas appliances have no supply (contact your gas supplier) or you suspect low gas pressure.

- If you see ignition sparking but no stable flame, smell gas, or have visible damage to the burner/ignition components.

- If the condensate or flue issues are not resolved by simple thawing or external clearing.

What the Gas Safe engineer will check/do:

- Measure gas pressure and supply, inspect and test the ignition electrodes and flame sensor, check and clean burners, inspect the flue and air supply, clear and test condensate drainage, run combustion checks and re-commission the boiler safely.

Final note:

E128 is a flame-safety lockout and should be treated seriously. Simple checks (reset, gas supply, thaw condensate, clear obvious external obstructions) are appropriate for a homeowner, but any work on gas, ignition or combustion components must be done by a Gas Safe registered engineer. If in doubt, or if the fault persists, arrange a professional visit.