Appliance category hub
Boiler Fault Codes
Browse boiler fault codes by brand with conservative guidance on display meanings, safe user checks, and when to contact qualified heating or gas help.
Brands covered
4
Code pages
92
Issue families
8
Safety guidance
Boiler guidance must stay outside the casing. Do not work on gas, combustion, flues, sealed components, or internal electrics. In the UK, gas work should be handled by a Gas Safe registered engineer.
Browse by brand
Baxi boiler codes
20 boiler code pages with meanings, safe checks, and escalation guidance.
Ideal boiler codes
18 boiler code pages with meanings, safe checks, and escalation guidance.
Vaillant boiler codes
28 boiler code pages with meanings, safe checks, and escalation guidance.
Worcester Bosch boiler codes
26 boiler code pages with meanings, safe checks, and escalation guidance.
Priority error-code pages
Vaillant Boiler F32
Fan, flue, or air pressure sensing problem
Vaillant Boiler F24
Water circulation or pump performance issue
Vaillant Boiler F25
Overheat protection fault
Vaillant Boiler F27
Flame detection has been lost during operation
Vaillant Boiler F28
The boiler failed during ignition
Vaillant Boiler F29
The boiler lost flame while running
Vaillant Boiler F75
Water circulation or pump performance issue
Ideal Boiler F9
The boiler is not seeing healthy water circulation
Vaillant Boiler F22
The heating system pressure is too low
Vaillant Boiler F23
System water pressure is too low
Worcester Bosch Boiler 101
Boiler has detected an overheat condition
Worcester Bosch Boiler 110
Model-dependent overheat or high-limit-style lockout
Find a code in this category
Filter by brand, issue family, severity, or code text.
92 of 92
Vaillant F32
highFan, flue, or air pressure sensing problem
fan flue
Vaillant F24
highWater circulation or pump performance issue
circulation
Vaillant F25
highOverheat protection fault
overheat
Vaillant F27
highFlame detection has been lost during operation
flame loss
Vaillant F28
highThe boiler failed during ignition
ignition
Vaillant F29
highThe boiler lost flame while running
flame loss
Vaillant F75
highWater circulation or pump performance issue
circulation
Ideal F9
highThe boiler is not seeing healthy water circulation
circulation
Vaillant F22
mediumThe heating system pressure is too low
low pressure
Vaillant F23
mediumSystem water pressure is too low
low pressure
Worcester Bosch 101
highBoiler has detected an overheat condition
overheat
Worcester Bosch 110
highModel-dependent overheat or high-limit-style lockout
overheat
Worcester Bosch 200
highHeating demand or controls signal issue
power control
Baxi E110
highthe boiler has overheated or reached a high-temperature safety limit.
overheat
Baxi E131
highthe boiler has locked out after an overheating or high-temperature condition.
overheat
Baxi E160
highthe boiler has detected a fan or air-pressure related fault.
fan flue
Vaillant F20
highthe boiler has reached an overheat or high-temperature safety limit.
overheat
Vaillant F64
highthe boiler has detected an internal sensor, electronics, or control-reading fault.
sensor
Worcester Bosch EA
highThe boiler failed to establish a flame
ignition
Baxi 133
highThe boiler has locked out after failing to light
ignition
Ideal F4
highThe boiler has failed to ignite on demand
ignition
Ideal L2
highThe boiler has lost or failed to prove flame
ignition
Worcester Bosch A1
highThe boiler is detecting poor water circulation
circulation
Baxi 125
highWater circulation or pump performance issue
circulation
Showing the first 24 matches. Narrow the filters to find a specific code faster.
Common issue families
sensor (26)
overheat (11)
PCB and control (10)
circulation (8)
fan and flue (8)
flame-loss (8)
low-pressure (8)
ignition (6)
Brands in this appliance category
Baxi
20 boiler code pages
Ideal
18 boiler code pages
Vaillant
28 boiler code pages
Worcester Bosch
26 boiler code pages
Related guides
Boiler Fault Codes: When to Stop and Call a Professional
Boiler issues need a more cautious approach than most white goods, especially where gas, combustion, or repeated lockouts are involved.
When to Call an Appliance Engineer
Guidance on recognising when simple checks have been exhausted and it is time to arrange a repair.
Why Your Boiler Keeps Losing Pressure
Learn the difference between a one-off pressure drop and repeated pressure loss, plus the safe top-up and recheck advice that stays within normal user controls.