Baxi error codes — full list with meanings | TroubleAtlas

🌐 ▾
HVAC Error Codes · Manufacturer index

Baxi error codes

The complete list of Baxi fault codes shown on the display, each with what it means and the page that explains how it is diagnosed and fixed.

49documented codes
49with documented causes
7.9TroubleAtlas Score
Baxi boiler with the fault code shown on the display
Quick Answer

Baxi heating appliances display 49 documented error codes. Each code below opens its own page with the official meaning, the documented causes, the safety assessment and the parts involved.

01

All Baxi Error Codes

49 codes, each with its own page. Click a code to open the meaning, the documented causes and the repair.

CodeWhat it meansSeverity
117Water pressure too high—
118Water pressure too low—
119System Pressure Low—
125Water circulation fault—
128Loss of flame during operationHIGH
133Safety time to establish flame exceededHIGH
162Air pressure switch error—
164Heating flow switch error (Ireland) Pressure Sensor Error (UK)—
166Air Pressure Switch Fault—
E0Temperature sensor fault—
E01Lockout due to no ignition—
E02Block for safety thermostat interventionHIGH
E04Safety error due to frequent flame losses—
E05Flow sensor faultHIGH
E06DHW sensor fault—
E09Gas valve wiring faultHIGH
E10Lack of consent of the hydraulic pressure switch—
E100Internal Clock Time Error on PCB—
E11Safety thermostat intervention for low temperature system (if connected)—
E110Boiler Overheat tripped – try bleeding your radiator—
E118System pressure low( 0.5bar (7.3 psi)—
E119Water pressure too low—
E125Primary Water Circulation Fault – try bleeding your radiators—
E128Loss of flame during operationHIGH
E129Loss of flame during calibrationHIGH
E130Flue NTC (Negative Temperature Coefficient) operation errorHIGH
E131Flue overheat lock out – this may follow a power cut, try resettingHIGH
E134Elapsed time gas valve open without gas (short request in a short period)HIGH
E15Gas valve connection faultHIGH
E163Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (s.c.) or DHW NTC…—
E164Heating Flow Switch Error (Ireland) Pressure Sensor Error (UK)—
E168PCB lock out – may follow a power supply problem, try resetting—
E20Central Heating Thermistor Sensor Fault—
E25Safety intervention due to lack of water circulationHIGH
E270Wrong power supply (Hz)—
E28Central heating thermistor sensor faultHIGH
E321Not water thermistor fault—
E35Parasitic flame (flame error)—
E384Flame detected when gas valve offHIGH
E4Poor circulation – ensure gas supply is turned on, if meter is a prepayment type ensure there is creditHIGH
E40Central heating return thermistor fault—
E430Water pressure temporary test—
E50Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (tank boiler) (s.c.)…—
E51Flue pressure switch intervention during boiler operation—
E53Flue pressure switch interventionHIGH
E54HW Flow Sensor Fault—
E7Ignition failure – try bleeding your radiators—
E92Water pressure sensor faultHIGH
E99Internal card error—
02

What Fails Most Often on Baxi

Grouped from the official meaning of each of the 49 codes above — not from opinion. The number is how many different fault codes point at that component.

ComponentCodesExamples
Ignition8128, 133, E01, E04
Water Pressure7117, 118, 119, E118
Temperature Sensor7E0, E163, E20, E28
Pressure Switch5162, 164, 166, E10
Pump4125, E125, E25, E4
Flue4E130, E131, E51, E53
Overheat3E02, E11, E110
Gas Valve3E09, E134, E15
03

Parts & Prices

The parts most often involved in the Baxi faults listed above.

Ignition / spark electrode
OEM Part · Baxi
Check price View price
Water pressure sensor
OEM Part · Baxi
Check price View price
Temperature sensor (NTC)
OEM Part · Baxi
Check price View price
Air pressure switch
OEM Part · Baxi
Check price View price
Compatible Ignition / spark electrode
Compatible · Generic
Check price View price
Compatible Water pressure sensor
Compatible · Generic
Check price View price
Compatible Temperature sensor (NTC)
Compatible · Generic
Check price View price
Compatible Air pressure switch
Compatible · Generic
Check price View price
Reconditioned Ignition / spark electrode
Used / Tested · Baxi
Check price View price
Reconditioned Water pressure sensor
Used / Tested · Baxi
Check price View price
Reconditioned Temperature sensor (NTC)
Used / Tested · Baxi
Check price View price
Reconditioned Air pressure switch
Used / Tested · Baxi
Check price View price

Prices and availability vary by region and are shown by the retailer, not by TroubleAtlas.

04

Diagnostic Tools

What an engineer uses to work through the codes on this page.

Digital Multimeter (TRUE RMS)

For testing electrode resistance and PCB voltages

$35–$80 View price

Gas Leak Detector

Essential for checking connections after any gas valve work

$25–$45 View price

Manometer / Pressure Gauge

To measure gas inlet and burner pressure

$40–$90 View price

Combustion Analyzer

For verifying flue gas readings after repair

$180–$350 View price
Full HVAC diagnostic toolkit
05

TroubleAtlas Score — Baxi

TROUBLEATLAS · SCORE INDEPENDENT · VERIFIED ★★ TA 7.9/10

How Baxi scores

Reliability9.0/10
Documentation8.8/10
Maintenance5.7/10
Safety8.2/10

Independently assessed across six dimensions from the documentation, the fault codes and the parts network. Based on 42 error codes across 124 appliances.

How we calculate it →
06

TroubleAtlas Pro

TroubleAtlas Pro — professional HVAC tools
For HVAC Professionals

Get cited by AI. Get found by customers.

TroubleAtlas Pro puts your business in front of homeowners searching for Baxi faults, and structures your listing so AI assistants can cite you as a trusted source.

Explore TroubleAtlas Pro →

Considering a New Heating System

Considering a New Heating System?

If your Baxi appliance is over 10 years old, replacing it with a modern condensing boiler or air-source heat pump could cut energy bills and remove the recurring faults listed on this page.

Compare Heating System Prices →
Professional heating system installation and service

YouTube Channel

TroubleAtlas · on YouTube

Watch the fixes. Follow the channel.

Step-by-step boiler repair guides, equipment reviews and heating system comparisons from qualified engineers.

New fixes every week
Weekly

Fix in 5

Quick fixes for common boiler faults explained in under 5 minutes

Head-to-Head

Boiler Comparator

Side-by-side comparisons of popular boiler models

Scored

Boiler Reviews

Independent reviews with TroubleAtlas Score ratings

Find a Specialist

Find help near you

Don’t fix it alone. Find a trusted heating engineer near you.

TroubleAtlas connects you with vetted local heating professionals who can inspect, diagnose and repair your Baxi appliance safely — no guesswork, no unnecessary call-outs.

VettedNear youDirect contact
Are you a professional? Join our network →
Suggested engineer · your city Certified heating technician

Local heating professionals are coming to your area

We’re onboarding Gas Safe registered and licensed HVAC engineers city by city. Check back soon, or search above to see current availability.

Written by TroubleAtlas Technical Team · Last updated: 2026-08-02 · Sources: manufacturer service documentation · How we verify
Scroll to Top