Baxi E.02-.48 Fault Code: Causes, Fixes & Repair Costs
What does the Baxi E.02-.48 fault code mean?
The E.02-.48 fault code (also displayed as A.02.48 on some Baxi models) indicates that the boiler has failed to successfully configure or establish communication with a paired external control device — such as a wireless thermostat, smart controller, or RF receiver. This is a locking error, meaning the boiler shuts down completely and will not restart until the fault is resolved and the boiler is reset. The underlying sub-code .48 represents a full configuration failure, extending beyond the general control bus connection error seen in .45, and points specifically to the boiler being unable to complete the pairing or configuration handshake with the external device.
General guidance only — not a substitute for professional advice. 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
- Lost pairing with wireless or smart thermostat Common
The most frequent trigger. After a battery change, power cut, or signal dropout, devices like the Baxi uSense, Hive, Nest, or Salus thermostats can lose their pairing with the boiler's receiver unit. The boiler detects the broken link during its configuration check and locks out.
- Power interruption resetting the control pairing Common
A mains power cut can cause the boiler's control panel to reset, wiping the stored pairing data for the external device. Even a brief outage is enough to trigger this fault when power is restored and the boiler attempts to reconnect.
- RF signal interference or excessive range Sometimes
Wireless room units must be within roughly 50 metres of the gateway or receiver. Thick walls, metal objects, or nearby electrical equipment can degrade the signal enough to prevent a successful configuration handshake, even within that distance.
- Loose or damaged wiring to the receiver unit Sometimes
The physical connection between the external device's receiver module and the boiler can develop loose terminals or damaged cable over time. A poor connection on the control bus prevents the configuration process from completing.
- Faulty receiver unit or external control device Rare
The receiver module itself — the component inside or near the boiler that handles the connection to the external controller — can fail. A defective receiver will consistently block the configuration process regardless of re-pairing attempts.
How to fix it
- Re-pair the external thermostat or controller DIY safe
Start by re-establishing the pairing between your thermostat and the boiler. For most wireless thermostats, switch the boiler off at the mains, remove the thermostat batteries, restore mains power to the boiler, then refit fresh, good-quality batteries to the thermostat. This prompts both devices to rediscover each other. Consult your thermostat's pairing guide for the specific button sequence required.
- Re-pair via the Baxi app (uSense and compatible smart controls) DIY safe
If you use a Baxi uSense or another app-connected smart thermostat, open the Baxi Thermostat app on your smartphone. Follow the in-app instructions to re-pair the smart device with your boiler. Ensure your phone has a stable internet connection and that the thermostat hub is powered throughout the process.
- Check the thermostat's position and signal path DIY safe
Make sure the wireless thermostat is within 50 metres of the boiler receiver and that there are no obvious sources of interference between them — such as other wireless devices, large metal appliances, or thick concrete walls. Moving the thermostat closer to the receiver can resolve borderline signal issues.
- Reset the boiler DIY safe
Once you have attempted re-pairing, press and hold the reset button on the boiler's front panel for 3–5 seconds until the boiler begins to restart. Wait for the startup sequence to complete and check whether the fault code clears. If the boiler locks out again with the same code, do not reset more than two or three times in quick succession — repeated resets without fixing the underlying fault will not help and may indicate a deeper problem.
- Call a Gas Safe registered engineer Gas Safe engineer
If the fault persists after re-pairing and resetting, the problem is likely a wiring fault on the control bus, a defective receiver unit, or a PCB configuration issue. A Gas Safe registered engineer can inspect the receiver module and wiring, carry out formal reconfiguration using the Baxi Works professional portal if needed, and replace any faulty components safely. Check whether your boiler is still within its warranty period (Baxi offer 2–10 years depending on installer accreditation) before booking a repair, as covered faults may be fixed at no cost.
Parts you may need
- RF receiver module · from £65
- Baxi uSense smart thermostat kit · from £85
- Wireless room thermostat (compatible third-party) · from £45
- Control bus wiring harness · from £30
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 £90–£280, depending on the underlying cause.
Frequently asked questions
Can I fix the Baxi E.02-.48 fault myself without calling an engineer?
In many cases, yes. Because this fault is fundamentally a pairing or communication failure between the boiler and an external controller, re-pairing the thermostat and resetting the boiler often clears it at no cost. Follow the re-pairing steps for your specific thermostat model, fit fresh batteries, and reset the boiler. If the fault returns after two or three resets, you will need an engineer to investigate wiring or hardware issues.
What is the difference between E.02-.48 and A.02.48 on a Baxi boiler?
They refer to the same underlying fault — a configuration failure with an external device. The difference is purely in how the display shows it: older or certain Baxi models present the code as A.02.48, while others use E.02-.48. Both mean the boiler has locked out because it cannot complete the configuration handshake with its paired external control. The diagnosis and fix are identical for both.
Could a PCB fault cause the E.02-.48 code, and how much does that cost to fix?
Yes, though it is uncommon. If wiring and the receiver unit are both in good order but the fault persists, the boiler's printed circuit board (PCB) may have developed a fault affecting how it handles external device configuration. PCB replacement is a job for a Gas Safe engineer and typically costs £280–£420 in total including parts and labour — considerably more than replacing a receiver or repairing wiring. It is worth ruling out the simpler causes first before assuming the PCB is at fault.
Will this fault be covered under my Baxi warranty?
It depends on the warranty level you have. All new Baxi boilers come with at least a 2-year manufacturer warranty, and boilers installed by a Baxi-accredited installer can carry up to 10 years of cover — provided the boiler has been serviced annually by a qualified engineer. If your boiler is within the warranty period and the fault is not caused by user error or third-party modifications, Baxi should cover the repair. Contact Baxi or check your warranty documentation before booking an independent engineer.