Baxi fault code E.02.35 means critical safety device disconnected. Baxi lists this wording for applicable Combi 2 and System 2 boilers.
The boiler’s controls are not detecting a safety device or safety connection they expect to be present. The code does not identify the device on the homeowner display, and it does not confirm that a single visible plug has simply come loose. Keep the boiler casing closed and arrange a qualified repair.
What does Baxi E.02.35 mean?
Modern boilers use several controls to check that operation stays within safe limits. E.02.35 indicates that the boiler has registered a disconnected critical safety device. Because the device is described as critical, the appliance should not be forced to run or bypassed.
The code is a starting point for an engineer, not a complete diagnosis. The exact safety circuit and reason for the message must be established using the correct service information for the model.
Which Baxi boilers use E.02.35?
Baxi includes E.02.35 in its current Combi & System 2 group. The listed ranges are the Baxi 200, 400, 600 and 800 Combi 2, the Baxi Assure 500 Combi 2, and the Baxi 600, 800 and Assure 500 System 2.
Other Baxi boilers may use different codes. Check the model name visible on the outside of the appliance and use only that model’s user guide. Do not apply instructions intended for another range.
Which safety device is disconnected?
The E.02.35 wording does not specify this for the homeowner. It would be unsafe to guess. A safety message can relate to a component, connection, control signal or another condition that prevents the boiler from confirming safe operation.
Only an engineer following Baxi’s model-specific procedures should identify the relevant circuit. Avoid online instructions that tell you to remove the casing, bridge terminals, reseat internal plugs or bypass a safety control.
Is Baxi E.02.35 dangerous?
The boiler has detected that a critical safety control is not available as expected. Treat that seriously and do not attempt to keep the appliance firing. The code does not by itself mean there is a gas leak or carbon monoxide present, but those warning signs always require emergency action.
If you smell gas, suspect carbon monoxide, hear a carbon-monoxide alarm or feel symptoms such as headache, dizziness, nausea or breathlessness, move into fresh air and follow current Gas Safe Register emergency guidance. Do not use electrical switches or investigate the boiler.
What can you safely check?
Useful homeowner checks are limited to what you can see without dismantling anything:
- Record E.02.35 exactly as displayed.
- Confirm the full boiler model from the outside label or user paperwork.
- Note whether heating, hot water or both have stopped.
- Check whether there has been a household power cut or tripped supply affecting the appliance.
- Record the visible system-pressure reading.
- Look for water around the boiler while avoiding wet electrical equipment.
- Note whether the fault appeared after servicing or other work, without touching any controls beyond normal user settings.
Do not remove covers, inspect internal connectors, test sensors or wiring, enter installer menus, or try to bridge or bypass any device. Never ask an unregistered person to work on a gas boiler.
Should you reset Baxi E.02.35?
Consult the user guide for your exact model. If it permits a homeowner reset, one careful attempt may be reasonable only when there is no smell of gas, carbon-monoxide warning, visible leak near electrics or sign of damage.
If E.02.35 remains or returns, stop resetting. A recurring critical-safety-device message needs professional attention. Repeated resets do not restore a missing safety signal and should not be used to keep the boiler running.
Can the boiler still be used?
Do not rely on the boiler while E.02.35 is displayed. It may have stopped heating or hot water because its controls cannot confirm the required safety condition. Use safe alternatives for warmth while arranging repair, and follow the manufacturer’s instructions for any portable electric heater.
Never use an oven, barbecue or outdoor heater to heat the home. If you are a tenant, tell your landlord or managing agent promptly, especially where children, older people or medically vulnerable occupants are affected.
What will an engineer do?
A Gas Safe registered engineer will confirm the exact model, examine the stored fault information and use Baxi’s service procedures to identify which required safety signal is missing and why. They can then repair the actual fault and verify safe operation.
The display alone does not justify replacing a sensor, PCB or other component. Correct testing matters because several conditions may produce a disconnection message, and safety controls must never be bypassed.
What information helps when booking?
Provide the full E.02.35 code, model name, visible pressure, whether heating or hot water works, when the message first appeared and whether there was a recent power interruption or boiler visit. Our boiler help guides cover other manufacturer messages, but all internal work should remain with the engineer.
Is your Baxi showing E.02.35?
Book Incredaboil’s fixed-price boiler repair for a clear price and an engineer visit aimed at fixing the safety-control fault and restoring normal operation.
Quick answers about Baxi E.02.35
What does E.02.35 mean on a Baxi boiler?
It means the boiler has detected that a critical safety device is disconnected.
Does the code identify which device is affected?
No. The homeowner display does not specify the device, and an engineer must use the exact model’s technical information.
Can I reconnect the device myself?
No. The relevant safety controls are inside the boiler. Do not remove the casing, touch connectors or bypass anything.
Can I keep resetting E.02.35?
No. Follow the exact user guide and, if it permits a reset, try it once. A code that remains or returns needs professional repair.