Baxi 400 Combi 2

With a history of over a century, Baxi has consistently been at the forefront of developing products that enhance comfort while maintaining environmental consciousness. The Baxi 400 Combi 2 boiler exemplifies this legacy, combining state-of-the-art technology with practical functionality to meet the modern homeowner’s heating needs.

The Baxi 400 Combi 2 is crafted to offer maximum efficiency in a compact design, making it an ideal choice for those with limited space. Its ability to fit discreetly within a kitchen cupboard highlights its practical design, while its energy efficiency and powerful performance cater to a wide range of domestic environments. Whether for a small flat or a larger family home, the Baxi 400 Combi 2 boiler provides a reliable and sustainable heating solution, reflecting Baxi’s dedication to quality and customer satisfaction.

Baxi 400 Comb Boiler 2 - Manchester Plumbing and Heating (Sale)

Baxi 400 Combi 2 Features

Compact Design

The Baxi 400 Combi 2 boiler is designed with space efficiency in mind, featuring dimensions that allow for installation in tight spaces, including kitchen cupboards. Measuring just 395mm in width, 700mm in height, and 285mm in depth, it exemplifies how compact design does not compromise power or performance. This sizing enables flexible placement options, making it an attractive solution for homes where space is at a premium. Integrating seamlessly into existing architecture without requiring extensive modifications underscores its design efficiency.

Efficiency and Performance

Energy efficiency is a hallmark of the Baxi 400 Combi 2, which meets and exceeds current environmental and operational standards. This boiler is engineered to maximise fuel efficiency, translating into significant savings on household fuel bills over time. High-efficiency boilers like the Baxi 400 Combi 2 use less energy to produce the same heat as older, less efficient models, reducing overall carbon emissions and enhancing household energy sustainability. For homeowners concerned about energy costs and environmental impact, this boiler offers a solution supporting economic and ecological sustainability.


Consumer confidence in the longevity and reliability of household appliances is critical, and Baxi understands this well. The Baxi 400 Combi 2 has a 5-year part and labour warranty, providing homeowners peace of mind knowing their investment is protected. This extended warranty period highlights Baxi’s commitment to quality and reliability, ensuring that any issues that may arise are addressed promptly without additional costs. Such a warranty not only enhances consumer confidence but also reflects the manufacturer’s assurance of the durability and performance of their product.

Technical Specifications

Power Variants

The Baxi 400 Combi 2 boiler is available in two power variants, 24kW and 30kW, designed to cater to the heating needs of various home sizes. The 24kW model is well-suited for smaller homes or apartments with one bathroom, providing adequate heat and hot water without excessive energy consumption. Conversely, the 30kW version is ideal for larger households with multiple bathrooms and a higher demand for hot water. These options allow homeowners to select a boiler that best fits their energy needs, ensuring efficient heating and hot water supply without compromising performance.

Technical Features

Durability and performance are the main features of the Baxi 400 Combi 2, emphasised through its high-quality construction materials. The boiler is equipped with brass hydraulics, known for their resistance to corrosion and mechanical durability, ensuring long-term reliability and fewer maintenance requirements. Additionally, it incorporates a stainless steel heat exchanger, which efficiently transfers heat and stands up well against wear and corrosion over time. An internal pressure gauge is another critical feature, providing users with easy monitoring and maintenance capability, ensuring the system operates within safe pressure levels at all times.

Compatibility Features

Future-proofing heating systems are essential, and the Baxi 400 Combi 2 is designed with this in mind. It is compatible with OpenTherm technology, which allows for integrating the boiler with third-party thermostats and controllers that use this protocol, offering enhanced control over home heating systems. This feature enables more precise temperature regulation and system monitoring, which can lead to further improvements in energy efficiency. Additionally, the boiler is ‘connectable boiler ready,’ meaning it is equipped to integrate with future connected services and smart home technology. This readiness ensures that the Baxi 400 Combi 2 can be easily updated or integrated as new advancements become available, providing users with a modern, adaptable heating solution.

Installation and Maintenance


The Baxi 400 Combi 2 boiler is designed with a focus on flexibility in installation, yet specific space requirements are essential to ensure safety and optimal performance. The boiler’s compact dimensions allow for installation in various locations, including inside kitchen cupboards. However, specific clearance is required: a minimum of 2.5mm to the sides, 240mm above, 250mm below, and 5mm in front during operation (expanding to 1000mm for servicing). These clearances ensure adequate ventilation and access for routine checks and servicing, thereby adhering to safety standards and enhancing the unit’s longevity.

Ease of Installation

Designed to facilitate a straightforward installation process, the Baxi 400 Combi 2 features a simple hanging bracket system. This system allows for quick and secure boiler mounting on most wall surfaces, including uneven walls, which is often challenging in older homes. Additionally, the top central flue position offers more flexibility in routing exhaust gases, accommodating various architectural layouts without extensive modifications. These features collectively reduce the complexity and duration of the installation process, making it less intrusive and more cost-effective for homeowners.


Regular maintenance is crucial to ensure any boiler’s efficient operation and longevity. The Baxi 400 Combi 2 is designed with accessibility in mind, making regular service and repairs straightforward for service technicians. Main components such as the heat exchanger, pressure gauge, and hydraulics are easily accessible, simplifying everyday maintenance tasks such as cleaning, pressure checks, and parts replacement. Moreover, the boiler’s design includes diagnostic interfaces that provide real-time data and fault codes, assisting technicians in quickly identifying and resolving issues. This approach minimises downtime and ensures that the boiler operates at peak efficiency, extending its service life and providing users with reliable heating performance.

Controls and Adjustability

Control Features

The Baxi 400 Combi 2 boiler has an intuitive user interface designed to simplify the management of home heating and hot water systems. This interface features straightforward controls allowing homeowners to easily adjust the temperatures for domestic hot water and central heating. The temperature settings can be finely tuned to meet personal comfort levels, with a range for domestic hot water typically between 35°C to 60°C and for central heating from 25°C to 80°C. These adjustable settings provide flexibility according to weather conditions and personal preferences and help optimise energy usage and reduce costs.

Advanced Diagnostics

The Baxi 400 Combi 2 incorporates advanced diagnostic features that actively monitor the boiler’s performance to ensure reliability and efficient operation. The boiler has a fault diagnosis display that alerts users to any operational issues, providing specific error codes that can help in quick troubleshooting. This system helps identify problems early, potentially preventing more serious issues and reducing downtime. Additionally, the boiler includes sophisticated temperature controls that constantly adjust the burning rate and water flow to maintain the desired heat output as efficiently as possible. This dynamic adjustment is crucial for extending the unit’s lifespan while maintaining optimal energy consumption. These diagnostic and control capabilities make the Baxi 400 Combi 2 an excellent choice for homeowners looking for a modern, dependable heating solution.

Safety and Operational Standards

Safety Features

The Baxi 400 Combi 2 boiler incorporates several critical safety features to protect the system and its users. The combined Pressure Relief Valve (PRV) and drain are crucial in maintaining the boiler’s internal pressure within safe limits. Should the pressure exceed safe operational levels, the PRV opens to release excess pressure, thus preventing potential damage to the boiler and the surrounding environment. Additionally, the boiler includes an integral frost thermostat, which protects the pipes from freezing during cold weather by automatically activating the heating when temperatures drop to a critical level.

Operational safeguards are embedded in the system to ensure it performs reliably under various conditions. These include sensors that monitor flame presence, exhaust flow, and system pressure, instantly shutting down the boiler if abnormal conditions are detected. Such automatic safety responses help prevent accidents and enhance the overall safety of the heating system.

Regulatory Compliance

The Baxi 400 Combi 2 meets stringent regulatory standards for safety and efficiency, which are crucial for user confidence and environmental stewardship. It complies with all relevant EU directives and UK regulations, which cover everything from installation and operation to emissions and energy consumption. The boiler’s design and construction are certified to ensure they meet these standards, ensuring it is safe and environmentally friendly.

The boiler’s high-efficiency rating aligns with energy-saving initiatives such as the Energy-related Products (ErP) Directive, which aims to improve the environmental performance of energy-consuming products. This compliance not only helps homeowners reduce their carbon footprint but also leads to significant savings on energy bills.

Accessories and Customisation


The Baxi 400 Combi 2 boiler offers a range of optional accessories that enhance its functionality and adaptability to user preferences. One customisable feature includes a variety of thermostat options. Homeowners can choose from basic mechanical thermostats to advanced smart thermostats that can be controlled remotely via smartphone apps. These smart thermostats provide greater control over heating schedules, adjust temperatures based on real-time weather conditions, and offer significant energy savings by optimising heating times based on user behaviour patterns.

Additionally, various programming kits are available that facilitate specific heating and hot water schedules, aligning with the household’s daily routines. These kits can program the boiler to heat water just in time for the morning rush and lower the heating when the house is empty, ensuring comfort while maximising energy efficiency.


To accommodate different installation environments and requirements, the Baxi 400 Combi 2 is compatible with several installation kits that enhance its flexibility and ease of integration into various home settings. One handy accessory is the optional stand-off frame, which provides extra space behind the boiler for pipework and fittings. This is especially beneficial in retrofit situations where space constraints may limit standard back-to-wall installation.

Other installation kits include flue extensions, bends, and vertical flue options, which are crucial for properties with unusual layouts or where the boiler needs to be installed away from an external wall. These kits ensure that the installation complies with safety standards regarding flue placement and emissions discharge, making it possible to install the boiler in the most convenient location without compromising performance or safety.

Together, these accessories and installation options allow homeowners to tailor the heating system to their specific needs, enhancing the boiler’s functionality and the overall user experience. By providing these customisation options, Baxi ensures that the 400 Combi 2 can meet a wide range of preferences and requirements, making it a versatile choice for many different types of properties.

Baxi Repairs and Service in Sale, Manchester

Dealing with a Baxi boiler breakdown is not just inconvenient—it can significantly disrupt your daily life, creating undue stress for families and particularly affecting those more vulnerable. At Manchester Plumbing and Heating (Sale), we understand the critical nature of these situations. As a leading Gas Safe Registered provider of Baxi boiler repair and services in Manchester, our goal is to deliver not only efficient but also amiable solutions tailored to the unique requirements of your Baxi gas heating system.

Our Promise to Baxi Boiler Owners

  • Prompt and Reliable Service:
    We know that time is of the essence when your boiler breaks down. Our team is committed to providing prompt service to ensure your heating system is back up and running as quickly as possible.
  • Expert Baxi Boiler Repair:
    Our engineers are not only skilled but also specifically trained to handle the nuances of Baxi boilers. This expertise means that you get the most reliable repair service that prolongs the life of your heating system.
  • Genuine Baxi Boiler Parts:
    We use only genuine Baxi parts for all repairs and replacements. This commitment to quality ensures optimal compatibility and performance, extending the durability of your boiler.
  • Transparent Communication:
    We believe in keeping our clients fully informed. From the initial diagnosis to the completion of the repair, our team maintains open lines of communication, ensuring that you are well informed about the progress and any decisions that need to be made.

Our service philosophy at Manchester Plumbing and Heating (Sale) extends beyond mere repairs. We aim to foster trust and provide peace of mind through the expertise of our Gas Safe registered engineers. Whether it’s an urgent repair or routine maintenance your Baxi boiler requires, you can rely on us for consistently reliable, friendly, and efficient service. Rely on Manchester Plumbing and Heating (Sale) for all your Baxi boiler needs in Sale, Manchester.


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