Baxi E.04-.13 Fault Code: Causes, Fixes & Repair Costs
What does the Baxi E.04-.13 fault code mean?
The E.04-.13 code is a permanent lockout fault on Baxi boilers, meaning the boiler has shut itself down completely and will not restart until the root cause is resolved and the fault is manually cleared. It tells you that the boiler's fan system has failed — either the fan rotor has jammed and can no longer spin, the fan motor has burned out, or the electrical wiring feeding the fan has been damaged or has come loose. The fan plays a dual safety role: it draws fresh air into the combustion chamber so gas can burn correctly, and it expels waste flue gases afterwards. Without a functioning fan the boiler's safety controls will not allow any gas to reach the burner, which is exactly why this fault causes a full lockout rather than a temporary error.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Seized or blocked fan rotor Common
Over time, debris, dust, or corrosion can cause the fan's rotor to jam solid. When the PCB attempts to start the fan and receives no movement feedback, it registers a permanent fault and locks the boiler out. This is the most frequently seen cause of E.04-.13.
- Fan motor failure Common
The motor that drives the rotor can burn out due to age, overheating, or electrical stress. A failed motor means the rotor simply cannot turn regardless of the signal sent to it. The boiler detects the absence of the expected fan speed signal and triggers the lockout.
- Damaged, loose, or corroded fan wiring Sometimes
The wiring harness connecting the fan to the PCB can suffer from loose connectors, heat damage, or corrosion — particularly in older boilers or those installed in damp locations. A broken circuit prevents the PCB from both powering the fan and reading its feedback signal, producing the same E.04-.13 fault even if the fan itself is physically intact.
- Poor installation or disturbed wiring Rare
On recently installed or recently serviced boilers, a connector may not have been seated properly or a wire could have been trapped or pinched during the work. This is less common overall but worth noting on newer installations that develop this fault early in their life.
How to fix it
- Reset the boiler once DIY safe
Locate the reset button on the front panel of your Baxi boiler (usually a flame symbol or labelled 'Reset'). Press and hold it for around three seconds, then allow the boiler to attempt a restart. If the boiler fires up and runs normally, monitor it over the next hour. If E.04-.13 reappears, do not reset again — repeated resets will not fix a genuine fan fault and could mask a developing safety issue. Move on to the next step.
- Check that your gas supply is working DIY safe
Turn on a gas hob or check that other gas appliances in the property are working normally. If no gas appliances function, the issue may be a wider supply interruption — contact your gas supplier. If other appliances work fine, the gas supply to the boiler is not the problem and the fan fault diagnosis stands.
- Call a Gas Safe registered engineer to inspect the fan assembly Gas Safe engineer
A qualified engineer will remove the boiler casing and visually inspect the fan rotor for physical obstructions, debris, or signs of seizure. They will also check the fan's electrical connectors and wiring harness for corrosion, loose pins, or heat damage. This inspection will confirm whether the issue is mechanical, electrical, or both.
- Engineer to test the fan motor electrically Gas Safe engineer
Using specialist diagnostic tools, the engineer will check whether the correct voltage is being supplied to the fan motor and whether the motor itself is producing the expected tachometer (speed) feedback signal to the PCB. This test distinguishes a motor failure from a wiring fault, which affects which component needs replacing.
- Engineer to replace the fan motor or full fan assembly as required Gas Safe engineer
If the motor has burned out but the fan housing is undamaged, the engineer may be able to fit a replacement motor alone — typically a cheaper option. If the rotor blades or housing are damaged, or a motor-only replacement is not practical for that model, the complete fan assembly will need to be swapped out. Only Baxi-compatible parts should be used to avoid voiding any remaining warranty.
- Engineer to clear the fault and recommission the boiler Gas Safe engineer
Once the repair is complete, the engineer will clear the permanent lockout from the boiler's fault log, carry out a flue integrity check, and run the boiler through a full heat and hot water cycle to confirm normal operation before leaving.
Parts you may need
- Baxi fan motor (replacement motor only) · from £60
- Baxi complete fan assembly · from £150
- Fan wiring harness / connector loom · from £25
- Fan speed sensor (tachometer) · from £35
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £180–£380, depending on the underlying cause.
Frequently asked questions
Can I fix the Baxi E.04-.13 fault myself?
The only safe DIY step is a single reset attempt. Beyond that, the fan is a safety-critical component directly linked to gas combustion and flue extraction, so any hands-on repair or replacement must be carried out by a Gas Safe registered engineer. Attempting to dismantle or bypass the fan system yourself is dangerous and will almost certainly void your Baxi warranty.
How much does it cost to fix the E.04-.13 fault on a Baxi boiler?
Most homeowners pay somewhere between £180 and £380 all-in for parts and labour. Where the engineer can replace just the motor rather than the whole fan assembly, the bill tends to sit towards the lower end. If quotes come in significantly above £450, it is worth getting a second opinion — there have been cases of engineers quoting over £690 for this repair, which is well above the typical market rate.
Why is E.04-.13 a 'permanent' fault rather than a temporary one?
Baxi boilers classify faults as temporary (the boiler retries automatically) or permanent (a full lockout requiring a deliberate reset). A fan failure is always treated as permanent because running the burner without a working fan risks incomplete combustion and a dangerous build-up of flue gases. The boiler therefore refuses to operate again until the fault is actively acknowledged and the underlying problem fixed.
My Baxi boiler is still under warranty — does that cover the E.04-.13 fan fault?
Baxi boilers come with a minimum two-year warranty, extendable up to ten years when installed by a Baxi-accredited installer and serviced annually. If your boiler is within its warranty period and has been regularly serviced, a fan failure should be covered — contact Baxi directly or your installing engineer rather than booking an independent repair, as using a non-approved repairer or non-Baxi parts could affect your warranty claim.