Baxi [E168] fault codewhat it means and how to fix it

E168 is a PCB lockout, and Baxi's installer guidance carries an unusually useful hint: it may follow a power supply problem, try reset. That single line is worth taking seriously, because it means E168 is not automatically an expensive diagnosis. Control boards do fail, but they also latch out after a voltage disturbance — a brownout, a supply interruption, or a spike from something else on the same circuit — without anything actually being broken. In that case a genuine power cycle at the fused spur, rather than a reset at the control panel, will often clear it outright. It is worth distinguishing E168 from its neighbours in the Baxi code set: E167 is a PCB fault, and E164 relates to a pressure sensor or flow switch depending on territory. Those are different conditions and quoting the wrong number sends an engineer down the wrong path. If a power cycle does not clear E168, or it returns repeatedly, then the board or the supply feeding it does need proper investigation.

1. 1

   Switch the appliance off at the fused spur — not just at the control panel — wait a full minute, and switch it back on. Baxi specifically suggest a reset for this code and a genuine power cycle is the thorough version.

2. 2

   Note whether anything else in the property has been misbehaving: lights flickering, other appliances tripping, or a recent power cut. That points at the supply rather than the board.

3. 3

   Check the fused spur or switch feeding the boiler looks sound and is not warm or discoloured. If it is either, stop and get an electrician — that is a fault in its own right.

   Do not remove the spur faceplate or investigate the wiring yourself unless you are competent to work on fixed electrical installations.
4. 4

   If E168 returns after a proper power cycle, book an engineer. Repeated latching after a clean power cycle points at the board rather than the supply.