Baxi Heat Pump Error Codes

Complete diagnostic guide for Baxi heat pumps in the United Kingdom.

Water Pressure and Flow Problems

Error codes for Baxi heat pumps related to water pressure, flow and circulation problems.

Error Code	Meaning	Possible Causes	Solutions
E10	Low water pressure	Water pressure in system too low Water loss due to leakage Bleeding problems in system Defective expansion vessel	Fill system to at least 1.2 bar (recommended: 1.0-1.5 bar) Check system for leaks and repair Bleed heating circuit completely Check expansion vessel and replace if necessary Check pressure switch and pressure gauge Contact qualified service if problem persists
F37	Water pressure too low	Water pressure sensor defective Expansion vessel defective Water pressure in system too low Leakage in system	Check water pressure and fill to 1.2-1.5 bar if necessary Test water pressure sensor for function Check expansion vessel Check system for leaks Replace sensor or expansion vessel if defective Contact qualified service
E25	Insufficient water circulation / Temperature difference too high	Circulation pump blocked or defective Blocked radiators Air in heating circuit Temperature difference between flow and return too high	Check circulation pump for function Check radiators for blockages Bleed heating circuit completely Check flow rate in system Monitor temperature difference Replace pump if necessary

Ignition and Flame Errors

Error codes for Baxi heat pumps related to ignition, flame monitoring and burner problems.

Error Code	Meaning	Possible Causes	Solutions
E01	Flame monitoring sensor	Ignition error - no flame detected Ignition electrode defective or contaminated Problems with gas supply Defective thermocouple Control board defective	Check ignition electrode and clean if necessary Check gas supply Check thermocouple and replace if necessary Check control board for errors Contact authorized service if problem persists
E04	Flame monitoring sensor	No flame formation Ignition electrode defective Problems with gas supply Control board defective	Check and clean ignition electrode Check gas supply Check control board for function Contact authorized service if problem persists
E35	Flame monitoring disturbed / Flame error (ionization)	Contaminated burner Ionization electrode defective or contaminated Problems with flame monitoring Burner not correctly adjusted	Have burner cleaned Check and clean ionization electrode Check flame monitoring Check burner settings Contact qualified service if necessary

Sensor and Temperature Errors

Error codes for Baxi heat pumps related to sensor, temperature measurement and overheating problems.

Error Code	Meaning	Possible Causes	Solutions
E02	Thermostat safety against overheating	System overheating Blocked pump Air in heating circuit Blockages in system Insufficient flow	Allow system to cool down Check pump for blockage Bleed heating circuit completely Check system for blockages Increase flow rate Contact qualified service if necessary
E06	Hot water sensor defective	Temperature sensor defective Sensor not properly connected Cable connection interrupted Sensor damaged	Check temperature sensor for function Check wiring for proper connection Test sensor with multimeter Replace temperature sensor if defective Contact authorized service
E03	Traction sensor	Error in flue system Air pressure switch defective Ventilation system blocked Problems with flue gas flow	Check flue system for blockages Test air pressure switch for function Check ventilation system Check flue gas flow for damage Contact qualified service if necessary

System and Communication Errors

Error codes for Baxi heat pumps related to system errors, electronics problems and communication failures.

Error Code	Meaning	Possible Causes	Solutions
E96	Electronics error	Control board defective Hardware error on board Electronic components damaged Problems with system configuration	Check control board for visible damage Restart system Check system configuration Have control board checked by qualified service Have board replaced if defective Contact qualified service for diagnosis
F40	Communication to gas valve disturbed	Communication error between control and gas valve Electronics problem Wiring damaged Control board defective	Check control and wiring Check communication connections Test electronics for errors Check control board for function Contact qualified service if necessary

Need More Help?

If you are experiencing problems with your Baxi heat pump that are not covered by these error codes, or if the provided solutions do not resolve your issue, we recommend:

Consult your Baxi heat pump user manual for model-specific information
Contact Baxi customer service in the United Kingdom for technical support
Seek help from a qualified heat pump repair technician
Check warranty coverage if your heat pump is still under warranty

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