01604 212732
7:30am - 10pm
Head Office: 3 Sunningdale Close, Northampton NN2 7LR
THS Plumbing & Heating Northampton
our gas safe id: 517522

Most common BAXI boiler faults

The E28, H02 – 06 and E133 are typically the most popular BAXI fault codes. We recommend that you call our boiler repair engineer for more info on the above fault codes.

Another common BAXI fault is 128, E50 and E54. These three fault codes are common and is either a diverter valve fault and broken burner. We stronly recommend that you get our BAXI boiler repair engineer.

BAXI Boiler Leaks – One of the most common faults

One of the most common BAXI boiler faults is a leaking boiler. Leaks can be a nightmare because not only can they cause water serious damage to your home, it can also cause damage to the electrical components inside the boiler.

What is the E133 fault?

The BAXI E133 fault code. Do you have the E133 fault code displayed on your BAXI boiler? What is the E133 fault and how do you fix it? The E133 fault has a wide range of possible faults connected to gas supply and igniton. When you see the E133 Fault on your BAXI boiler its means the boiler has failed to ignite. No gas supply (check gas supply – gas valve or PPM has credit), temperature outside is below zero and blocked condensate.

The E133 fault can be fixed just by checking that your gas valve ECV is turned on, also checking if your pre paid meter has credit, if you have one. Also check the condensate pipework because in the winter this can freeze and stop your BAXI boiler from working.

BAXI Fault Meaning Possible Causes
E133 Failed to ignite, Ignition fault Boiler won’t ignite/failed: No gas or insufficient gas, ignition fault (Ran out of credit on the gas – Pay as you go only), check your condensate pipe

BAXI Platinum, EcoBlue, Duo-tec and BAXI 200, 400, 600, 800

Fault/Error Code Possible Cause
H01 – 00 Communication Fault – Temporary loss of communication between gas valve, check for loose connections
H01 – 05 Sensor error – The flow and return temperature exceeded. Engineer required
H02 – 06 Water leak – System water pressure, check for water leaks. Water leak on boiler or system. Engineer required
E00 – 05 – 04 Sensor fault – Sensor not or badly connected, check connection. Return temperature sensor open-circuit.
E09 Gas valve cable – Gas valve connection, connection cable. Engineer required
E10 Probe fault – External probe fault.
E12 Switch fault – External probe fault.
E13 Switch fault – Still open, differential water flow switch fault. Engineer required
E15 Gas command fault – Gas valve command fault. Engineer required
E20 Thermostat fault – Central heating negative temperature coefficient (baxi NTC) thermostat fault. Engineer required
E28 Thermostat fault – Flue negative temperature coefficient (baxi NTC) thermostat fault. Engineer required Duo-tec – Flue thermistor error.
E40 Thermostat fault – Central heating return negative temperature coefficient (baxi NTC) thermostat fault. Engineer required
E50 Thermostat fault – Central heating return negative temperature coefficient (baxi NTC) thermostat fault. Engineer required
E83 – E84 – E85 – E86 – E87 Thermostat fault – No communication. Engineer required
E118 Pressure too low – Below 0.5 bar. Primary system water pressure too low.
E128 Flame failure – More than 12 times. Frequent flame failure. Engineer required
E160 Fan fault – Also check fan cables. Fan fault. Engineer required
E163 DHW – NTC Sensor fault – Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (s.c.) or DHW NTC sensor fault (o.c.). Engineer required
Light- 1 green flash No action required – Boiler temperature reached. Your boiler is running perfectly
Light- 3 green flash Flame loss – Boiler will self reset. Keep an eye on this, if fault continues you will see 3 red flashes.
Light- 4 green flash Communication error – Temporary error, boiler will self reset. Communication error between printed circuit board (PCB) and control.
Light- 5 green flash PCB error – Temporary error, boiler will self reset. Parameter error on printed circuit board (PCB).
Light- 6 green flash Temporary error – Temporary error, boiler will self reset.
Light- 1 red flash Sensor error – Temperature fault or flow fault. Engineer required
Light- 2 red flash Overheat – Boiler overheat tripped. Engineer required
Light- 3 red flash Ignition fault – Boiler has attempted to light 5 times and failed. Engineer required
Light- 4 red flash Fan fault – Fan not working, Fan fault. Engineer required
Light- 5 red flash (PSU) error – Parameter storage unit.
Light- 6 red flash Boiler error – Boiler Fault – Engineer required

Head Office:

THS Plumbing & Heating Northampton

3 Sunningdale Close



Tel: 01604 212732

Open: Monday-Sunday 7:30am - 10:00pm

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