Fault guide
Baxi E168, the catch-all fault code
E168 is Baxi's general fault code. It is the boiler saying something is wrong without saying what, which is exactly why it needs diagnosing properly rather than guessing.
Why a general code exists
Boiler control boards monitor a long list of inputs: sensors, the fan, the pump, the flame signal, pressure and the wiring between them. When something falls outside the expected range but does not map to a specific coded fault, Baxi boilers report E168.
It frequently appears alongside or immediately after another code, and that other code is usually the more useful clue.
What is usually behind it
In the properties we cover, E168 has generally turned out to be one of these.
- Low system pressure or poor circulation causing sensor readings to drift.
- A failing flow or return thermistor giving impossible temperature readings.
- Fan speed feedback out of range, or a fan on its way out.
- Loose, corroded or damp wiring connections, especially in garages and lofts.
- A PCB fault, which is the last thing we conclude rather than the first.
Before you call
Two quick things are worth checking yourself.
- Check the pressure gauge reads roughly 1 to 1.5 bar cold and top up if it does not.
- Note any other code that appeared before E168, and tell us when you call.
How we diagnose it
We read the fault history from the boiler, test each sensor against actual measured temperatures, check fan speed feedback, inspect the wiring and connectors, and verify circulation and pressure. Only when everything else tests good do we look at the control board.
A PCB is an expensive part, and we are not in the habit of fitting one to a boiler that turned out to have a damp connector.
Questions we get asked
- What does E168 mean on a Baxi boiler?
- E168 is a general boiler fault. Unlike a specific code it does not name the component, it tells you the control board has seen something it does not like and has stopped.
- Is E168 serious?
- Not necessarily, but it does need diagnosing rather than resetting. Because it is a catch-all code, the underlying fault could be anything from a loose wire to a failing PCB.
- Can I clear E168 myself?
- You can reset the boiler once and check system pressure. If the code returns, it needs an engineer with test equipment, because the code alone does not identify the cause.