Facebook pixel
new boiler

Get a new boiler

Fixed price boilers, next day

See boiler prices
new air conditioning

Air Conditioning

Get a quote
new heat pump

Heat Pumps

Coming soon

new ev charger

EV Chargers

Get a quote
boiler servicing

Boiler Servicing

Get a quote

Last updated: 7th January, 2024


Biasi Boiler Error Codes - How To Fix

Biasi Boiler Error Codes - How To Fix

Key takeaways

  • Biasi boiler error codes are key to identifying and solving issues.
  • Certain errors can be resolved with a system reset, while others need further action.
  • Regular maintenance may prevent common error codes from occurring.

Understanding the error codes on your Biasi boiler is the first step in troubleshooting. Some error codes are more prevalent and indicate specific issues, often involving ignition failures or the need for a system reset.

In the realm of home heating systems, Biasi boilers have established a solid reputation for reliability and efficiency.

However, even the most dependable boilers can encounter issues, manifesting in the form of error codes. 

These codes are crucial for diagnosing and addressing faults within the system. Understanding what each error code signifies is essential for both homeowners and technicians to quickly rectify problems and maintain boiler operation.

Need a new boiler?

Get a quote in 60 seconds, fitted as fast as next day!
0% APR finance available.

Get a quote

Error codes such as ER 03, ER 07, ER 10, and ER 14 appear on the boiler’s display to alert users to specific malfunctions. Each code provides insight into the nature of the issue, whether it’s related to water pressure, temperature sensors, or gas supply, and necessitates distinct corrective actions. 

Some errors might only require a system reset to resolve, whilst others could indicate the need for more comprehensive maintenance or professional repairs.

Common Biasi Boiler Error Codes

Understanding the error codes on your Biasi boiler is the first step in troubleshooting. Some error codes are more prevalent and indicate specific issues, often involving ignition failures or the need for a system reset. Below, key error codes are detailed, providing you with insight into their meanings and initial reset procedures.

ER 01 + Reset

Error code ER 01 signifies an ignition failure in the Biasi boiler. This indicates that the boiler has not ignited after several attempts. Check for potential blockages in the flue or condensate pipe, inspect if there's sufficient gas supply, and ensure all valves are open. To reset, press the designated reset button on the boiler interface for about three seconds. If the issue persists, professional assistance is advised.

ER 02 + Reset

ER 02 is a fault code that reflects problems with the boiler's heating circuit, signifying an overheating condition. Reasons could include a defect in the pump, low water pressure, or air within the system. Ensure the pressure gauge readings are within the recommended range and bleed radiators if necessary. For a reset, once any issue is resolved, press and hold the boiler's reset button. Should the fault code reappear, a professional engineer's expertise may be required to investigate further heating components.

ER 03 + Reset

This section provides insight into the commonly encountered ER 03 error code on Biasi boilers and outlines the steps for resetting the boiler after addressing the issue.

ER 04 +

The ER 04 error code signifies a faulty fan within the Biasi boiler. A malfunctioning fan impedes the boiler's ability to expel hazardous gases, leading to a safety lockout to prevent further risk. To resolve this, a Gas Safe engineer should inspect and potentially replace the fan. Post-repair, the boiler can usually be reset by following the manufacturer's guidelines, which typically involve holding down the reset button for three seconds.

ER 05 +

When an ER 05 error code appears, it is indicative of problems with the pump. The pump's role is crucial in circulating hot water within the heating system. If the pump is faulty, a lockout may occur to prevent damage to the boiler. A fix can be attempted by a local engineer, who may either repair or replace the pump. After a successful repair, the heating engineers will reset the boiler to restore its normal function.

ER 06 +

An ER 06 error code alerts users to a burner ignition fault. This fault could originate from several issues, including a blocked burner, a failure in the ignition leads, or issues with the boiler's electrical connections. Troubleshooting should be conducted by qualified heating engineers to diagnose and repair the specific cause. Once resolved, the boiler must be reset, a process that involves interruption of the power supply to the boiler or a manual reset as advised by the manufacturer.

ER 07 +

The ER 07 error code on a Biasi boiler indicates a safety lockout due to a failed ignition attempt. This requires immediate attention to ensure safe operation. Isolating the issue can reduce liability and restore the boiler to its functional state, but if it persists, a Gas Safe engineer should be consulted.

ER 08 +

When facing an ER 08 error, this typically signifies that the boiler has encountered an issue with the fan or flue, preventing safe removal of combustion gases. Homeowners must not try to fix these components themselves due to the hazardous nature of the work involved. Instead, they should:

  • Contact a Gas Safe registered engineer: Only professionals should deal with gas-related issues to guarantee safety.

  • Schedule regular servicing: Preventive maintenance can help avoid such errors by ensuring that all components are in working order.

ER 09 +

The ER 09 error code often arises when the boiler detects a water pressure fault. Steps to resolve this error may include:

  • Checking the pressure gauge: Ensure that it reads within the manufacturer's recommended levels.

  • Repressurising the system: This can sometimes rectify the issue if the pressure is too low. Homeowners can refer to the boiler manual for guidance on how to safely repressurise their system.

To deal with an ER 09 fault effectively, timely action is essential. If homeowners are unable to rectify the problem themselves, they should seek professional assistance promptly to prevent potential damage or further issues.

ER 10 + Reset

The ER 10 error code on a Biasi boiler often indicates a failure in the flue or a problem with the air pressure switch. This malfunction can lead to the boiler ceasing operation as a safety measure to prevent any potential harm.

ER 12 +

The ER 12 error code suggests a discrepancy in the operation of the diverter valve, which allocates hot water between heating and domestic use. The valve may be stuck or failing to function properly, often resulting in either the radiators or the taps being without hot water.

  • Possible Cause: Stuck diverter valve

  • Symptom: Lack of hot water in radiators or taps

  • Resolution: Check the diverter valve for obstructions or signs of failure; a reset may rectify the issue temporarily, but the valve typically requires cleaning or replacement for a long-term solution.

ER 13 +

Encountering an ER 13 error code points towards an issue with the boiler's flame detection. This could be due to a faulty burner, a problem with the gas supply, or the printed circuit board (PCB) not communicating correctly.

  • Troubleshooting steps:

    1. Inspect the burner for any visible signs of damage or malfunction.

    2. Verify the consistency and availability of gas supply.

    3. Examine the PCB for any error indications or failure signs.

Important: While resetting the boiler can sometimes restore its function, it is essential to address the underlying cause promptly to ensure the safe and efficient operation of the heating system.

ER + 14 +

Error ER + 14 signifies a pump fault, which often leads to issues with heating and radiator functionality. This code points to potential problems in circulation that need to be resolved to restore optimal boiler performance.

ER + 14 + Reset

To address the ER + 14 fault, one should initially attempt a system reset. A simple reset can often clear transient errors. However, if the problem persists, it's indicative of a deeper circulation issue, possibly a seized pump or a blockage impeding the flow of water.

ER + 19 +

The ER + 19 error code may signal a fault with the central heating temperature probe. It's the component responsible for monitoring the water temperature in the system. If this probe fails, it could result in the boiler misreading the central heating’s temperature, leading to inadequate heating performance.

ER + 25 + Reset

For ER + 25, a reset might once again resolve the error temporarily. However, this particular code often points to a more serious fault involving the diverter valve — a crucial part that routes hot water to either the radiators or the taps. Should the diverter valve be defective, hot water may not be allocated correctly, affecting both heating and domestic hot water supply. Faults with the gas valve may also manifest similarly, with impacts on burner ignition and potential banging noises indicating inconsistent gas flow.

ER + 69

The ER69 error code on Biasi boilers indicates a problem related to wiring or electronic components. This issue demands attention to specific aspects such as connections and circuitry to ensure the boiler operates reliably.


When the Biasi boiler displays an ER69 error, it suggests a lockout due to an electrical fault. The user should inspect the wiring for any loose connections, signs of wear, or damage. Should an individual be unfamiliar with electrical systems, it is prudent to seek professional assistance. Boiler repairs involving electrical components must be conducted by a Gas Safe registered engineer, considering the complexity and potential risks involved.


Regular maintenance is critical for the longevity and reliability of gas boilers. In case the ER69 error is set off by a fault in the electronic components, these parts might need a replacement. A reliable engineer should perform a comprehensive diagnosis to ascertain if a new boiler component is required. Occasionally, a replacement boiler might be more cost-effective, and acquiring a boiler quote from a certified provider is advisable. This determination largely depends on the age and overall condition of the current system.

Preventative Measures

Taking proactive steps to maintain a Biasi boiler can pay dividends, reducing the likelihood of faults and enhancing the system's efficiency.

Reducing the Risk of Future Issues

Regular Servicing: Arranging for a Gas Safe registered engineer to service the boiler annually is paramount. This not only ensures the system operates at peak efficiency but also brings to light any potential issues that could spiral into costly repairs.

  • Pressure Checks: Maintain the correct water pressure and top up as necessary. Low water pressure, often indicated on the boiler's pressure gauge, can lead to inefficiencies and potential heating malfunctions.

  • Bleeding Radiators: Release trapped air from the radiators to avoid airlocks, which can affect circulation and heat distribution.

  • Cleaning: Keep boiler components clean, particularly the heat exchanger, to prevent boiler overheating and inefficiency.

  • Clear Condensate Pipe: In cold weather, ensure the condensate pipe is insulated to prevent freezing, which can lead to blockages and a shutdown of the boiler.

By embracing preventative maintenance measures, the lifespan of a Biasi boiler can be significantly extended, keeping the home warm and energy usage in check.

Get a quote

Frequently Asked Questions

What are boiler fault codes?

Boiler fault codes are alphanumeric or numeric codes displayed on the control panel of a boiler. They signal specific issues or malfunctions within the system, enabling users or engineers to identify and address the root cause of a problem.

What is error code 02 on a Biasi boiler?

Error code 02 on a Biasi boiler suggests a problem with the boiler's thermistor. This typically means the thermistor is detecting water temperatures that are too high, potentially due to scale buildup or a fault within the thermistor itself.

How do I reset my Biasi boiler?

To reset a Biasi boiler, one should locate the reset button, which is usually situated on the boiler's control panel. Press and hold this button for about five seconds. If the boiler does not reset or the fault recurs, professional assistance may be required.

What is the FL code on a Biasi boiler?

The FL code on a Biasi boiler indicates a flame loss during operation. Causes could include gas supply issues, faulty ignition, or problems with the flame detection electrode. Following safety protocols, check these components or seek a Gas Safe registered engineer's help.

Are Biasi boilers any good?

Biasi boilers are generally considered reliable and effective for domestic heating. They are known for their affordability and have a presence in the UK market, with a reputation for cost-effectiveness.

Where are Biasi boilers made?

Biasi boilers are manufactured in Italy. The company has a long history, dating back over 75 years, and their boilers are now available across various markets, including the UK.

Stephen Day profile photo
Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.