The Baxi A.02.45 code means “Connection error.” That is the complete wording in Baxi’s current error-code information. It indicates that an expected technical connection has not been established or recognised, but the public description does not identify the connection, cable, control or device involved.
Record A.02.45 exactly, check the full model name and note whether heating and hot water still work. Do not open the boiler or start unplugging controls. If the message stays or comes back, arrange a professional repair.
What does Baxi A.02.45 mean?
A.02.45 is a connection error within the boiler’s controls environment. The message can help a qualified engineer begin fault-finding, but it is not a complete explanation of the underlying problem. It does not say that a visible internet connection, Wi-Fi signal or room thermostat has definitely failed.
Because Baxi does not name the affected connection in its public table, it would be unsafe to guess. The exact appliance, installed controls, recent work and accompanying messages all matter.
Which Baxi models use the A.02.45 code?
Baxi currently lists A.02.45 for a group containing Baxi 200, 400, 600 and 800 Combi 2 models, Baxi Assure 500 Combi 2, Baxi 600 and 800 System 2, and Baxi Assure 500 System 2. The code should not automatically be applied to every Baxi boiler.
Find the full model on the user guide, commissioning paperwork or an accessible external label. Keep the casing closed. Model-specific information allows the engineer to check the right technical documentation.
Does connection error mean Wi-Fi or thermostat trouble?
Not necessarily. Homeowners often search for A.02.45 after losing heating control, but the manufacturer’s short description does not state that the error concerns Wi-Fi, a thermostat, an app or any named accessory. The phrase “connection error” can refer to technical communication within the appliance or its configured system.
You may check whether ordinary external controls have power or whether a battery-powered thermostat display is blank, provided this is covered by the user instructions. Do not unpair devices, bridge terminals, move wires or change installer settings.
What can you safely check before a repair?
A few external observations can help:
- Check that the code is A.02.45, including punctuation.
- Photograph the display and any other message that appears.
- Record the complete boiler model.
- Note whether heating, hot water or both are affected.
- Check the visible status of ordinary room controls without changing technical settings.
- Note whether the code followed a power cut, installation, service visit or control-related work.
Do not remove covers or unplug devices as a test. A connection that looks secure from outside may not be the connection described by the code, and disturbing it can make the original fault harder to trace.
Can you reset a Baxi A.02.45 fault?
Use the normal reset once only if the official user guide for your exact model tells you how. Baxi reset controls vary between models. If A.02.45 immediately returns, reappears later or normal heating and hot water do not resume, stop resetting and arrange a repair.
Do not perform a factory reset or enter installer, commissioning or parameter menus. A technical connection problem cannot be safely corrected by experimenting with settings.
What should you not try?
Do not open the boiler casing, check plugs or connectors, test wiring or voltages, or attempt work on the control board. Do not copy a configuration from another boiler and do not buy a replacement thermostat or PCB on the strength of A.02.45 alone.
The code does not prove that a particular part is defective. Professional testing is needed to distinguish a configuration issue, interruption, connection problem or another cause relevant to the exact installation.
Is a Baxi A.02.45 code dangerous?
Baxi’s published description is a connection error, not a gas-leak warning. However, the boiler should never be dismantled, bypassed or repeatedly restarted. If it behaves unusually, makes concerning noises or displays additional safety-related messages, turn it off using the normal user control if safe and obtain advice.
If you smell gas, suspect carbon monoxide, feel unwell near the appliance or hear a carbon-monoxide alarm, leave the property and follow the current emergency guidance. Do not wait for a routine repair visit.
Who can repair Baxi A.02.45?
A suitably qualified Gas Safe registered engineer should investigate a persistent connection error. They can confirm the appliance model, identify the relevant communication path safely and carry out the appropriate repair. Your notes about the display, recent work and which services are affected will give them useful context.
Keep the boiler closed and continue only with ordinary user actions stated in the exact model guide.
Ready to deal with the A.02.45 connection error?
Book a fixed-price boiler repair aimed at fixing the fault, with the booking price clear before the visit.
Quick answers about Baxi A.02.45
What does A.02.45 mean on a Baxi boiler?
Baxi defines it as “Connection error.” The public wording does not identify the affected connection.
Is A.02.45 definitely a thermostat fault?
No. It may affect how the system operates, but the code does not name a thermostat, Wi-Fi link or other specific device.
Can I reconnect wires or controls?
No. Keep the boiler closed and do not disturb wiring, terminals or configured devices. Those checks need the right competence.
Should I reset the boiler?
You may try the normal reset once if the official guide for your exact model instructs you to. A code that returns needs a repair.
Does A.02.45 mean I need a new PCB?
No. The code does not prove that any particular component has failed. An engineer must assess the appliance first.
What details should I record?
Note the exact code, complete model, whether heating or hot water is affected, other display messages and any recent power interruption or work.