Andrews E09 Fault Code: Causes, Fixes & Repair Costs
What does the Andrews E09 fault code mean?
The E09 fault code on Andrews (Andrews Water Heaters by Baxi) boilers signals that the boiler's main control board (PCB) is not receiving a valid feedback signal from the gas valve. In practical terms, the PCB expects confirmation that the gas valve is operating correctly; when that confirmation is absent or interrupted, the boiler locks out as a safety precaution. The fault points specifically to the gas valve connection cable circuit — either the wiring between the valve and the PCB, or the gas valve itself. Because Andrews Water Heaters is now part of the Baxi group and shares control architecture with Baxi-family products, the E09 code carries the same meaning across the related product range.
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
- Loose or disconnected wiring at the gas valve Common
Vibration over time, or disturbance during a previous service, can cause the connector plug at the gas valve to work loose. A poor connection breaks the feedback circuit and triggers E09. This is the most frequently identified cause and is straightforward for an engineer to confirm and correct.
- Damaged or deteriorated cable between the gas valve and PCB Common
The cable run from the gas valve to the control board can chafe against metal edges, suffer heat damage, or simply degrade with age. A break or short within the cable prevents any signal reaching the PCB, producing the same E09 lockout as a loose connector.
- Failed gas valve Sometimes
If the gas valve itself has seized, corroded internally, or suffered an electrical failure within its coil, it will produce no feedback signal regardless of the wiring condition. Gas valve failure is a more serious and more costly outcome but should be considered once wiring has been ruled out.
How to fix it
- Check the boiler's gas supply is active DIY safe
Confirm that other gas appliances in the property (hob, fire) are working normally. If there is no gas supply to the property, contact your gas supplier rather than resetting the boiler.
- Reset the boiler once or twice following the manufacturer's procedure DIY safe
Locate the reset button or reset sequence on your Andrews unit (refer to your user guide). Hold or press as directed and wait for the boiler to attempt a restart. If E09 returns immediately or after a short while, do not continue resetting — repeated resets without resolving the underlying fault can cause further wear.
- Check whether the unit is still within Andrews' two-year warranty DIY safe
Andrews Water Heaters provides a two-year parts-and-labour warranty on units commissioned by Andrews. If your appliance is within this period, contact Andrews Water Heaters by Baxi on 0345 070 1058 before arranging independent repairs, as the work may be covered at no cost.
- Arrange inspection of the gas valve wiring and connector by a Gas Safe registered engineer Gas Safe engineer
An engineer will check the connector plug at the gas valve for looseness, corrosion, or burn marks, and trace the cable back to the PCB looking for chafing, breaks, or heat damage. Tightening a loose plug or replacing a damaged cable is often all that is needed to clear E09.
- Gas valve testing and replacement if wiring is sound Gas Safe engineer
If the wiring proves intact, the engineer will test the gas valve electrically to determine whether the valve coil or internal components have failed. A faulty gas valve must be replaced — this is gas-system work and is illegal and dangerous to attempt without Gas Safe registration.
- PCB inspection if the fault persists after valve and wiring are confirmed good Gas Safe engineer
In rare cases where both wiring and the gas valve test correctly, the PCB's input circuit for the valve feedback signal may be damaged. A Gas Safe engineer working alongside an approved Andrews/Baxi technician can assess and replace the PCB if required.
- Call a Gas Safe registered engineer if E09 persists or recurs Gas Safe engineer
If you have not already done so, contact a Gas Safe registered engineer to carry out a full diagnosis. You can verify an engineer's registration at gassaferegister.co.uk. Do not attempt to access or adjust the gas valve, its wiring, or the PCB yourself — this is both dangerous and illegal without the appropriate Gas Safe qualifications.
Parts you may need
- Gas valve connection cable / wiring harness · from £25
- Gas valve (Andrews/Baxi-compatible replacement) · from £120
- Main PCB (control board) · from £200
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 £120–£320, depending on the underlying cause.
Frequently asked questions
Can I fix the Andrews E09 fault myself?
No. While the first steps — checking your gas supply is on and attempting a reset — are safe for a homeowner to carry out, any work beyond that involves the gas valve and its associated wiring, which are gas-system components. UK law requires that all work on gas fittings be carried out by a Gas Safe registered engineer. Attempting this yourself is illegal and potentially life-threatening.
How much does it typically cost to fix an E09 fault on an Andrews boiler?
For the most common cause — a loose connector or damaged cable — you should expect to pay roughly £120–£200 all-in, covering the engineer's call-out, diagnosis, and a straightforward wiring repair. If the gas valve itself has failed and needs replacing, the cost typically rises to around £250–£320 including parts and labour for a standard residential-type unit. Commercial or large-output Andrews water heaters use heavier-duty valves that can cost considerably more; in those cases, discuss the parts cost with your engineer before authorising the work.
Why does E09 keep coming back after a reset?
A reset clears the lockout flag but does nothing to address the underlying fault. If E09 returns shortly after a reset, the gas valve is still not sending a valid signal to the PCB — meaning the wiring fault or valve failure is still present. Repeated resets without a repair can accelerate wear on other components. Book an engineer rather than continuing to reset the boiler.
My Andrews boiler is relatively new — could it be covered under warranty?
Andrews Water Heaters by Baxi provides a two-year warranty covering parts and labour on units that were commissioned by Andrews. If your unit is within that period, contact Andrews on 0345 070 1058 before arranging an independent repair, as a valid E09 fault caused by a manufacturing defect or early component failure may be repaired at no charge.