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Last updated: 30th January, 2024


Baxi Boiler E125 Error Code

Baxi Boiler E125 Error Code

Key takeaways

  • The E125 error code indicates a circulation problem in Baxi boilers.
  • It can often be resolved by checking and adjusting the boiler pressure.
  • Some cases may require attention from a Gas Safe registered engineer.

Boiler systems are intricate and can exhibit a range of error codes that signal specific issues. Here, the focus is on what these error codes mean and why they are essential for maintaining your boiler's health and efficiency.

The Baxi boiler E125 error code is a common issue that users may encounter, signalling a problem with the water circulation in their heating system. This error suggests that the boiler has detected poor circulation of heated water, which can be due to a variety of factors including low system pressure. 

Understanding and diagnosing this error code is essential for homeowners to maintain the performance and efficiency of their heating systems.

Addressing a Baxi boiler's E125 error involves a series of checks and balances, from verifying system pressure to assessing the pump function. Although some underlying causes can be resolved by the user, such as repressurising the boiler, other issues may require professional intervention. 

Identifying signs of circulation errors early on can prevent more extensive damage and ensure that heating systems continue to operate safely and effectively.

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What Is a Boiler Error Code?

Boiler systems are intricate and can exhibit a range of error codes that signal specific issues. Here, the focus is on what these error codes mean and why they are essential for maintaining your boiler's health and efficiency.

Explain What Boiler Error Codes Are in General

Error codes on boilers are alphanumeric or numeric codes displayed on the boiler's control panel. They act as diagnostic tools, providing a quick indication of the system's current status or malfunctions. 

These codes are generated by the boiler's internal sensors and monitoring systems when they detect inconsistencies or failures in operation. For instance, error code E125 in a Baxi boiler commonly points to circulation problems, which can be indicated by symptoms such as low pressure within the system.

Importance of Understanding Error Codes for Boiler Maintenance

Recognising and interpreting these error codes is a key aspect of boiler maintenance. They allow homeowners and engineers to identify and respond to issues swiftly, often before the problem escalates. Understanding error codes helps in:

  • Preventing damage: Early detection of faults can prevent further damage to the boiler and connected systems.

  • Maintenance scheduling: Specific error codes can inform owners when a boiler requires servicing.

  • Cost efficiency: Addressing issues promptly through understanding error codes can save on lengthy and expensive repairs.

  • Safety: Some error codes may indicate potential safety risks; knowing these helps ensure the continued safe operation of the boiler system.

By decoding these signals, users are empowered to take informed actions, whether that's resetting the system, topping up the pressure, or calling a Gas Safe registered engineer for assistance.

What Does the Baxi Boiler E125 Error Code Mean?

In addressing a Baxi boiler displaying the E125 error code, one encounters a situation that often denotes circulation problems. This section aims to elucidate the significance of the E125 code and explore common culprits for its appearance.

Detailed Description of the Specific Error Code

The E125 fault code is indicative of a circulation fault in a Baxi boiler. This error highlights the struggle of the heating system to maintain adequate water circulation -- a vital aspect for the boiler's optimal functioning.

Possible Reasons Why This Error Code Appears

Several reasons can contribute to the onset of the E125 fault code. Firstly, low pressure within the system stands as a predominant factor. A boiler operates effectively within certain pressure parameters; deviations may trigger error codes.

Airlocks, blockages, or pump failure are other potential reasons. They impede water flow, causing the system to fall short of its required operational standards. Significantly, any resolution involving the removal of boiler casing or tampering with gas appliances should be conducted by a Gas Safe registered engineer.

Signs of the Baxi Boiler E125 Error Code

In addressing the E125 error code displayed by a Baxi boiler, it's essential to understand the signs indicating this particular issue.

List and Explain Common Signs and Symptoms That Indicate This Specific Error

  • Low Pressure: One will often notice the pressure gauge indicating lower than the recommended levels.

  • Altered Hot Water Supply: There may be inconsistencies in the supply of hot water, a symptom tied to circulation issues.

  • Cool Radiators: Despite active heating settings, radiators may remain cool, pointing towards poor circulation within the system.

  • Presence of Leaks: Occasional leaks could occur, which can contribute to a drop in pressure and the triggering of the E125 error.

  • Boiler Noise: Unusual noises emanating from the boiler, such as knocking or gurgling, indicate circulation faults that are common precursors of the E125 error code.

Can I Fix This Boiler Error Code Myself?

  • Repressurising the System: Homeowners might manage to increase pressure by repressurising the system if they are familiar with the process and follow safety guidelines.

  • Bleeding Radiators: Air caught in the radiators can be released by bleeding them, potentially resolving minor circulation problems.

However, while some insistent homeowners tackle these steps, it's prudent to involve a Gas Safe registered engineer, especially when the issue persists. Ignoring or misdiagnosing these signs could lead to further complications.

Do I Need to Contact a Gas Safe Engineer to Fix This Error Code?

Navigating boiler error codes can be vexing; however, the presence of an E125 error code on a Baxi boiler is one of those situations that necessitates professional intervention.

Advice on When It's Necessary to Call a Professional

The E125 error code typically indicates a circulation fault in the boiler, which can stem from issues such as low water pressure or a pump failure. Consequently, it's imperative to engage with a qualified heating engineer who can safely diagnose and rectify the issue. Homeowners should note that attempts to fix boiler problems without the requisite expertise not only pose risks to personal safety but may also contravene legal regulations related to boiler repairs.

  • Yes: If you encounter the E125 error code.

  • No: For routine pressure checks or topping up, refer to the user manual.

Explanation of What a Gas Safe Engineer Is and Why Their Expertise Is Important

A Gas Safe Engineer is an individual who has undergone rigorous assessment and is legally registered to work with gas appliances in the UK. This certification is a non-negotiable requirement for anyone intending to repair or install gas boilers. Their expertise is vital because:

By employing a Gas Safe registered engineer to address the E125 error code, homeowners guarantee that the boiler repair or service is compliant with the latest safety standards and industry best practices.

How Much Does Fixing the Baxi Boiler E125 Error Code Cost?

Repairing a Baxi boiler that is displaying the E125 error code varies in cost and largely depends on the complexity of the fault and the components involved. To address this error, an engineer's expertise is often required.

General Cost Range for Fixing This Error (Can Be an Estimate or Based on Average Rates)

Typically, homeowners can expect the repair cost for an E125 error code on a Baxi boiler to range between £80 and £200. This estimate takes into account a standard engineer call-out fee and basic labour charges. However, the cost may escalate if the issue persists beyond a simple fix or requires replacement parts.

Factors That Might Affect the Cost


  • The complexity of the error often stems from components like the heat exchanger, pump, or valves. If these components require cleaning or replacement, the cost will reflect the price of the parts plus labour.


  • A certified engineer's experience and rates will also influence the final invoice. Repairs conducted by a Baxi-certified engineer may command a premium, but there is a guarantee of quality service and genuine parts.

It's crucial for homeowners to acquire a precise quote after an initial diagnostic by a professional to avoid unexpected costs and ensure a reliable resolution to the E125 error code issue.

Do I Need a New Boiler?

Navigating the treacherous waters of boiler breakdowns, homeowners may face the E125 error code on their Baxi boiler. This may raise concerns about whether to opt for repairs or to consider the purchase of a new boiler entirely. The following delineates criteria for decision-making, outlines typical boiler lifespans, and gives a brief overview of the costs involved in replacement.

Criteria to Decide Whether a Repair Is Sufficient or if a New Boiler Is Required

  • Age of the Boiler: If the boiler is close to or beyond its expected lifespan, which typically lasts between 10-15 years, replacement might be more cost-effective than repair.

  • Frequency of Breakdowns: Regular malfunctions indicate that the boiler system is failing and may require a new installation.

  • Cost of Repairs: Should the cost of fixing the E125 error and any associated faults exceed 50% of replacing the boiler, investing in a new system is advisable.

  • Energy Efficiency: Modern boilers offer higher energy efficiency. If the current boiler is inefficient, a new system could reduce energy bills substantially.

  • Safety Concerns: Persistent issues may pose safety risks. An unreliable boiler should be replaced to ensure safety.

Information on the Lifespan of Boilers and When Replacement Is Typically Recommended

Most boilers have a lifespan of around a decade or more. However, the precise timing for replacement depends on several factors:

  • Maintenance: Regular, professional servicing can extend a boiler's lifespan.

  • Manufacturer: Some brands are known for their longevity, while others may have a shorter operational life.

  • Usage: Higher usage can lead to more wear and tear, potentially shortening a boiler's effective lifespan.

  • Model: Certain models might be more durable than others, influencing the decision on when to replace.

New Boiler Costs

Boilers can be a daunting purchase for many people as they’re an appliance with a lot of responsibility, providing heat for you and your family is something you want to get right. Boilers aren’t exactly a quickly disposable item either, potentially lasting you a decade.

New boiler cost can be split into two segments: the first is the actual boiler itself (unit price), and the second is the cost of the boiler being installed (set up) in your property by an expert engineer. 

Here at iHeat, we want to remove all of this undue stress and make the decision making process of upgrading to a new central heating system, as easy as possible.

Boiler costs can vary depending on a number of factors including their brand, model, fuel, output, warranty, labour and installation type. Typically a new boiler will cost between £1,845 and £3,500, below is a list of average boiler installations offered by iHeat (guide only).

Installation Type

Price (inc VAT)

Combi to combi swap


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System to combi conversion


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New boiler install


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Back boiler to a combi


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System to system


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In this section, the intricacies of the E125 error code on a Baxi boiler are distilled into core insights, affirming an understanding of the issue's origins and rectification methods.

Summarise the Key Points Discussed in the Blog Post

The E125 error code signifies a water circulation fault in Baxi boilers, where the system struggles to pump heated water through the pipework, radiators, or towel rails. Potential culprits for this include blockages, pump failures, or system leaks.

  • Causes:

    • Obstructed pipes or radiators

    • Pump malfunction or degradation

    • Airlocks within the heating system

    • System leaks reducing pressure

  • Solutions:

    • Checking and cleaning pipes and radiators

    • Inspecting the pump for operational integrity

    • Bleeding radiators to remove airlocks

    • Sealing leaks and repressurising the system

The troubleshooting process should begin with simpler fixes like bleeding radiators and inspecting for obvious leaks before proceeding to more complex tasks such as dismantling components to check for blockages. Should these attempts fail to resolve the fault, professional assistance is advised.

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Frequently Asked Questions

How do I fix E125 error on a boiler?

The E125 fault code on a Baxi boiler indicates a circulation problem, usually resulting from low water pressure. One can remedy this by increasing the pressure within the system, often by topping up the boiler via the filling loop.

How do I reset my Baxi boiler error code?

Resetting a Baxi boiler error code typically involves locating the reset button on the boiler's control panel and pressing it. For some models, holding the button for a few seconds might be necessary. However, if the issue persists, professional assistance may be required.

What is error code 125 on Baxi 600?

Error code 125 on the Baxi 600 series relates to a water circulation fault. This problem could be due to a number of issues such as a defective pump, blocked pipes, or air trapped within the system, highlighting the need for thorough troubleshooting or professional repair.

Can I fix an L2 boiler fault myself?

An L2 fault code on a Baxi boiler signals ignition issues. While some fixes can be straightforward, such as checking for gas supply or resetting the boiler, it's prudent to seek a Gas Safe registered engineer for complex faults especially if self-troubleshooting fails to resolve the error.

How do I fix my E125 boiler error?

Fixing an E125 boiler error involves checking the system's pressure and re-pressurising it if it's low. The process for re-pressurising is generally straightforward and well-documented in the boiler's manual, but persistent or recurring errors should be examined by a professional.

What is the E125 fault on the Main Eco Compact?

The E125 fault code on the Main Eco Compact indicates the same circulation issues as on other Baxi models. The compact design might necessitate specific procedures for resolution, which will be detailed in the owner's manual, but revolves around checking for adequate system pressure.

Why is my Baxi boiler flashing green?

A flashing green light on a Baxi boiler typically signifies that the boiler is operating in standby mode or that there might be a temporary operational issue. If the light continues to flash and the boiler doesn't function, consulting the manual or contacting a technician is advisable.

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.