E168 is a general Baxi fault code. It means the boiler has logged a problem without pinpointing a single cause, and it often shows up straight after another fault code. Seen by itself, E168 does not tell you what has gone wrong, only that something has. The sections below cover what tends to cause it, what you can safely check yourself, and when it is time to bring in a Gas Safe engineer.
What Does E168 Mean?
E168 is a general fault, not one tied to a single part or sensor. It most often appears after another code, commonly E119, E125, E133 or E156, and the sequence varies by boiler model. Confirm the exact definition and recommended action for your model against the official Baxi manual, since detail can differ across the range.
The usual reason is simple. When the boiler is reset after a fault, it may no longer detect the original problem, so it shows E168 in its place. That means the code itself is less useful than whatever happened just before it.
Common Causes
E168 can point to several different things, so it is worth narrowing down before assuming the worst.
| Cause | What it looks like |
|---|---|
| Earlier fault code | Another code appeared first, and E168 followed it |
| Unstable power | The fault shows up after a power cut or voltage dip |
| Faulty component | A problem with the gas valve, fan, pump, electrode, diverter valve or internal wiring |
| Control board fault | The boiler gives inconsistent or unreliable readings |
An earlier fault code is the best place to start, because fixing that problem usually clears E168 too. Unstable power is the next thing to rule out. Baxi boilers are designed to run on 230V within about 10% either way, and a supply that dips outside that range, often only at certain times of day, can trigger a fault that is hard to catch. A faulty component is harder to spot without opening the boiler, because a worn electrode or a sticking fan can behave inconsistently before it fails outright. A control board fault is usually the last thing checked, once the other causes have been ruled out.
What Code Came First?
If you caught the code that appeared just before E168, it can point an engineer in the right direction before they even arrive.
| Code before E168 | Likely connection |
|---|---|
| E119 | System water pressure too low. See our guide to the Baxi E1 fault code |
| E110 | The overheat thermostat has tripped. See our guide to the Baxi E110 fault code |
| E125 | The boiler got too hot because water was not circulating properly |
| E133 | The flame failed to light in time, often a gas supply or ignition issue |
| E156 | The mains voltage dropped below what the boiler needs |
| E20 | A problem with the boiler temperature sensor |
| E28 | A problem with the flue gas temperature sensor |
| E50 | A problem with the hot water temperature sensor |
| E130 | The flue gas temperature went too high |
| E160 | A problem with the fan |
Baxi’s user guides say the pressure gauge should normally read between 1.0 and 2.0 bar, and that the system needs topping up through the filling loop once it drops below 1.0 bar. That is the one cause in this table you can usually fix yourself. The others need an engineer to test the part involved.
These are likely connections, not certainties, and the relationship between codes can vary by model, so check the handbook for your own boiler.
What You Can Safely Check Yourself
- Note which code showed on the display just before E168. This sequence is often the most useful clue for whoever diagnoses it.
- Check the pressure gauge and top up through the filling loop if it is below 1.0 bar.
- Reset the boiler once at most. Repeated resets rarely fix the underlying issue and can make it harder to trace.
- If you have had a recent power cut, flickering lights or other electrical problems, have an electrician check the supply.
Do not open the boiler casing, bypass a sensor or safety device, or keep pressing reset in the hope it clears on its own. The casing keeps gas and electrical parts safely away from anyone without the right training, and bypassing a safety device turns a fault into a safety risk.
It is also worth writing down when the fault happens. If E168 only shows up at certain times of day, after the heating comes on from cold or straight after a power cut, that pattern helps whoever diagnoses it and can save a second visit.
When to Call a Gas Safe Engineer
Once you have noted the earlier code and ruled out low pressure and an obvious power issue, the rest is for a professional. Gas parts, such as the valve or electrode, and the control board should only be tested, adjusted or replaced by a Gas Safe registered engineer. In the UK, gas work on a domestic appliance is legally restricted to registered engineers, and you can check any engineer’s registration on gassaferegister.co.uk.
An engineer called out for E168 will usually start by checking the system pressure and the fault history stored on the boiler, then test the parts most likely to be involved based on the code that appeared first. Having the make and model of your boiler to hand, along with a note of when the fault happens, helps them get to the right part faster.
How Much Does a Repair Cost?
There is no single price for an E168 repair, because the cost depends on what is actually wrong. Topping up low pressure costs nothing, while replacing a control board sits at the other end of the scale. An engineer can only give you a firm figure once they have diagnosed the fault in person.
BeFix charges £95 an hour between 7am and 5pm, £125 an hour between 5pm and 9pm, and £160 an hour between 9pm and 7am, all plus VAT, with no call-out fee. Any parts needed are priced separately and confirmed once the fault has been diagnosed.
If you want a rough idea before booking, think in terms of time. A fault with a clear earlier code is usually quicker to trace. An intermittent fault, such as a power supply that only dips at certain times, can take longer to pin down. Either way, the hourly rate above is the only number that applies until an engineer has seen the boiler. BeFix (Gas Safe 967796) carries out boiler repair in London, and you can book an engineer through that page.
Frequently Asked Questions
What does E168 mean?
E168 is a general Baxi fault code. It means the boiler detected a problem but could not identify one specific cause, often because another fault appeared and cleared just before it. On its own, it is a signal to investigate further, not a diagnosis.
Can I reset the boiler myself?
A single reset is usually fine and sometimes clears a one-off glitch, such as one caused by a brief power dip. Resetting repeatedly is not recommended, since it will not fix an underlying fault and can make the original problem harder to trace.
Is it safe to keep using the boiler?
It depends on what triggered E168, which the code alone does not tell you. If the fault keeps returning, or followed a gas or ignition related code, it is safer to stop using the boiler and have a Gas Safe engineer check it before you rely on it again.
Is E168 serious?
E168 itself is a general flag, so it is not automatically serious. Because it can sit behind a gas, electrical or component fault, it should not be ignored, particularly if it keeps coming back.
What causes E168?
It is commonly linked to an earlier fault code, unstable mains power, a faulty component such as the gas valve, fan, pump or electrode, or a control board giving unreliable readings. The exact cause needs a hands-on check to confirm.
Why does E168 keep coming back?
A recurring E168 usually means the underlying issue was never resolved, even if a reset temporarily cleared the display. Resetting clears the fault from view without fixing whatever triggered it, so if it keeps coming back, the fault needs proper diagnosis.


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