Boiler Error Codes

The most common error codes.

Error Codes for Vaillant Boilers & Worcester Bosch Boiler Error Codes

Boilers are mostly reliable and will give you little to no bother over the years with regular maintenance and servicing. However, from time-to-time issues may arise that prohibit the boiler from working to its fullest. There is no right time for your boiler to break down and stop working, especially as it’s such an important part to the inner working of the home. 

Thankfully, your boiler will tell you where the fault will most likely be arising from in the form of error codes. Below are the most common error codes you will find on common Vaillant boilers and Worcester Bosch boilers Read on to learn more.

Boost Plumbing offer boiler servicing, central heating services and can install new gas boilers in Bristol, Bath, Keynsham, Saltford, Peasedown St John and across BANES and Somerset. 

Vaillant Boiler Error Codes

Heating flow temperature sensor interruption.

Return temperature sensor interruption.

Defective plug connection to NTC or defective NTC.

Interruption cylinder sensor actoSTOR, due to defective NTC cable, connection or plug.

Failure to Ignite due to possible lack of gas or fault with ignition.

Failure to Ignite due to insufficient gas supply or ignition defect.

Overheated system causing to lock out.

Central Heating Flow NTC Fault due to defective NTC cable or incorrectly fitted flow thermistor.

Flow NTC short circuit.

Heating Flow NTC Thermistor Fault.

Short circuit at cylinder charging sensor.

F13: NTC defective, short  circuit in cable harness.

Electricity supply to boiler is less than 170v.

Overheating boiler that needs to cool down.

Low water pressure.

Temperature difference too great.

Water Circulation Fault.

Flue gas temperature too high.

Incorrect flame detected.

Unsuccessful ignition.

Unsuccessful reignition.

Fault in fan detected.

Fault detected in the air/ flue gas duct.

Fault between the coding resistor and PCB.

Short circuit eBUS.

Fault with mass flow detected.

Fault in gas supply.

Fault detected in mass flow sensor regulation.

Ignition electrode probably highly corroded.

Gas valve actuation fault.

Delayed gas valve switch off.

Fault in circuit board probably due to age and wear.

Fault found with boiler electrics.

PCB Temperature too high

Flame signal fault.

Unstable flame signal fault.

Invalid device specific number.

Heating flow thermistor defected.

Water pressure sensor signal in wrong range.

No pressure change detected.

Primary heat exchanger overheated.

Blockage in condensate pump or malfunction.

Coding resistor fault.

Gas group fault.

Worcester Bosch BOILER Error Codes

Incorrect HCM fitted.

Code plug fault.

Replace control board.

Running too fast or running too slow.

Fan not running or fan not running or airflow blocked.

Sensor wet or damaged.

Boiler overheated.

Flow sensor shorted or damaged.

Flow sensor disconnected or damaged.

Flow sensor disconnected or damaged.

Primary flow sensor overheated.

The main heat exchanger has overheated; temperature sensor has failed.

Failure of four ignition attempts, gas valve coil disconnected or error where the pump is not detecting water

Little or no water in the system

Fan has stopped

The boiler is operating at minimum burner load.

Air lock or reduced water content

Sensor disconnected or no water content.

get in touch today

Boilers are incredibly dangerous and require Gas Safe registered engineers to service them, such as us here at Boost Heating and Plumbing. Our qualified and experienced engineers service and maintain boilers across Bristol, Bath and surrounding areas. Get in touch today by calling our Bristol team on 0117 9000986 or Bath 01225 632349 or Contact Us via the website. 

Boost Plumbing offer boiler servicing, central heating services and can install new gas boilers in Bristol, Bath, Keynsham, Saltford, Peasedown St John and across BANES and Somerset. 

Get in Touch