Baxi 400 Combi 2.1 Boiler Cost with Installation

Baxi is a reputable brand, and the 400 Combi 2.1 model features durable components, including brass hydraulics and a stainless steel heat exchanger. It also comes with a 5-year parts and labour warranty, making this a combi boiler you can trust.

Learn more about this model’s specifications in the table below. 

Baxi 400 Combi 2.1 Product Table
	Available outputs	24kW	30kW	36kW
	Model name	422	430	436
	Type	Combi	Combi	Combi
	Fuel	Gas	Gas	Gas
	Condensing	Yes	Yes	Yes
	Efficiency Rating (%)	94	94	94
	ErP	A	A	A
	LPG Compatible	Yes	Yes	Yes
	Standard Warranty	5 years*
	Max Output (kW)	24	30	36
	Flow Rate (l/min)	10.2	12.2	15.0
	Mounting	Wall mounted
	Dimensions (mm)	700 x 395 x 285
	Typical Price (inc VAT)	£740 – £800
	Typical Installation Cost (inc VAT)	£1,200
	Total Cost	£1,940 and £2,000

*Terms and conditions apply.

Baxi 400 Combi 2.1 overview

The Baxi 400 Combi 2.1 is a popular boiler model, with many unique features. It’s built to be compact and run with minimal noise, so you can install it almost anywhere! 

Baxi offers three models in this range, with outputs suitable for different homes, as outlined below. 

Baxi 400 Combi 2.1 Range
Model output size	House size	Bathrooms	Radiators
24kW	Flats, small homes 1 to 3 bedrooms	1	Up to 10
30kW	Medium homes 3 to 4 bedrooms	1-2	Up to 15
36kW	Medium to large homes 4 – 5 bedrooms	2	Up to 20

This boiler model is best suited for those with small or medium-sized homes. The 24kW option is great for flats or smaller properties that need to supply 1 bathroom and up to 10 radiators. However, there is an option for larger properties, as the 36kW model can cope with the demands of a home with up to 2 bathrooms.

If you have a larger property, however, with 2 or more bathrooms, a combi boiler might not be the best option for you, as they struggle to supply multiple water outlets simultaneously. If you have a particularly high hot water demand, you could consider the Baxi system boiler range instead. 

Benefits at a glance 

Baxi have packed a lot of great features into the 400 Combi 2.1 model, some of the key benefits include:

• Lightweight design makes installation quick and easy
• Energy efficiency of 94% and an ErP A rating (reducing emissions and lowering energy bills)
• Quiet operation (49-50 dB)
• 5-year warranty that includes parts and labour 
• Compatible with natural gas or LPG (without a conversion kit)
• Compatible with the Baxi uSense smart thermometer for greater control
• Built with brass hydraulic and stainless steel heat exchanger for longevity 

Baxi 400 Combi 2.1 technical specifications

The Baxi 400 Combi 2.1 offers homeowners a highly efficient option at a competitive price point. It’s also backed by a 5-year warranty and is made with materials that last. This model is an excellent option for those who want to reduce emissions, save on bills and want something simple and reliable.

Of course, there are lots of complexities going on below the case, so let’s explore some of the technical specifications that make this a model worth considering.

Output and efficiency

As we’ve seen, Baxi offers the 400 Combi 2.1 in three outputs (24kW, 30kW and 36kW), and while each can provide instant heating and hot water, they also operate at an efficiency level of 94%. This is amongst the highest combi boiler efficiencies currently on the market.

At this level, you’ll benefit from an almost complete return in heat output for the fuel that’s burned. This means less energy waste and a reduction in your bills (compared to running an older, inefficient model). 

Each model is also rated ‘A’ on the ErP scale, indicating that its environmental footprint is low, with low emissions during use and a great energy use performance.  

Dimensions 

If you’re concerned about the available space in your home, this boiler is a good solution. Its compact dimensions allow it to be installed in almost any space, such as a kitchen cupboard.

Each model in the range is 700mm in height, 395mm in width, and 285mm in depth. This small size also makes it much easier to install, which can reduce your overall fitting time and costs. 

Components included

When you choose the Baxi 400 Combi 2.1, you benefit from some great internal features and components. This includes a pre-heated condensate trap, for example, which helps prevent pipes from freezing during winter. 

There is also an external pressure gauge so that you can top up the pressure yourself, without having to call out an engineer. 

This model is also compatible with the Baxi uSense smart thermostat, giving you the ability to control your boiler remotely from a smartphone app.

Features like these help extend your boiler’s lifespan and give you a greater level of control. This means you’re less likely to need to pay out for engineer support over the long term. Combine this with the 5-year warranty, and you have even greater peace of mind.

Prices and installation costs

The Baxi 400 Combi 2.1 unit costs between £740 and £800, depending on the output size. Installation for a boiler of this size is typically around £1,200, so your total will be between £1,940 and £2,000 for a full installation.

Baxi 400 Combi 2.1 Costs
Output size	Unit cost	Total incl. installation
24kW	£740	£1,940
30kW	£780	£1,980
36kW	£800	£2,000

These prices are only indicative, based on our market research and actual boiler prices submitted to WhatPrice by homeowners. 

To get a more accurate price estimate for your installation, you should request quotes from up to 3 Gas Safe registered installers. They can give you tailored advice and pricing based on your circumstances. When you get multiple quotes, you can compare them to ensure you’re getting the best deal.

You can also use the WhatPrice Boiler Cost Calculator to get a more detailed price estimate on your installation costs. 

Warranty and support

Baxi offers a 5-year warranty for the 400 Combi 2.1, which includes parts and labour. While this is a good warranty offer, it’s not as long as some other brands include as standard.

Currently, Baxi doesn’t offer warranty extensions for this model. If this is an important element in your purchasing decision, you might want to take a look at their 800 or Platinum ranges instead, which currently offer 10-year warranties.

The Baxi 400 Combi 2.1 standard warranty covers most mechanical failures and faults and includes the boiler, controls, replacement parts and labour. 

However, like all warranties, there are specific terms and conditions that need to be met in order to maintain the warranty’s validity. This includes installation by a Gas Safe registered engineer, regular servicing, and correct registration of the warranty. 

The warranty should be registered within 30 days of installation (by the installer or homeowner). This can be done online at Baxi’s warranty portal or by phone. The Benchmark commissioning checklist must also be completed following installation. 

Baxi offers customer support and aftercare for repairs, maintenance and boiler services. They can be contacted by phone or online, via their website.

Installation information

If you choose to replace your boiler with a new Baxi 400 Combi 2.1, there are some steps to the installation process that are good to know. Your installation could cost around £1,200 and will depend on the installer you choose, their local rates and any other additional parts or upgrades you need.

What to expect on installation day

These steps are purely a rough guide, as every home is different. You may find that additional steps are needed if you have any significant upgrades or replacements done. For example, if you are swapping boiler types or moving the boiler’s location, this can take longer and require more parts/time. Your installer should always give you an estimate of the timeframe upfront alongside any quotation. 

Do you need a system flush or filter?

It is always recommended that you get a system flush performed as part of your new boiler installation. A system flush removes the sludge and debris that have built up on your old heating system before the new boiler is installed. This prevents any damage to your new boiler from occurring when you turn it on.

Sludge and debris build up over time and can cause pipes to erode. This erosion affects the performance of your boiler and can damage internal parts. This can lead to major faults and expensive breakdowns.

One great way to help prevent the damage of this debris is to install a filter with your new boiler. While these are not a requirement, they can be instrumental in prolonging your boiler’s lifespan. They will capture any debris before it can enter the boiler, protecting it from internal damage. 

Finding a Gas Safe registered engineer

It’s a legal requirement in the UK that gas boilers may only be installed by a Gas Safe registered engineer. These qualifications ensure your boiler is fitted to the highest safety standards and in compliance with current regulations.

Finding a Gas Safe registered installer is simple, as you can search and verify any installer’s credentials via the Gas Safe Register website. Alternatively, you can use the WhatPrice quote service, where all of the recommended installers are fully vetted.

Reviews and ratings

Baxi is a highly rated UK brand with a great customer review rate. Their overall score on a site like Trustpilot, for example, is 4.6 out of 5, with over 70,000 reviews, giving them a rating of ‘Excellent’.

Some of the key elements customers and installers love about Baxi boilers are the competitive pricing, high efficiency levels and that they are easy to install. When it comes to the Baxi 400 Combi 2.1, we’ve found that reviews are mostly positive, but there are some downsides to consider. 

Positive reviews 

The Baxi 400 2.1 is frequently praised by customers for its compact design, which allows for a more flexible installation. Both homeowners and installers like that it operates so quietly, so it can be less distracting in a smaller home.

Its small size also makes it easier to lift and position, which installers say is a bonus compared to other brands.

The user-friendly and smart control options are a plus, while the high efficiency levels make it a good choice for energy-conscious households. 

The inclusion of features like a stainless steel heat exchanger and a pre-heated condensate trap gives the boiler longevity, which makes users more confident in the product’s quality.

Customers feel this is one of the best budget to mid-range combi boilers, noting its affordability compared to other models. Baxi’s UK-based customer support also receives consistent praise, and its responsive engineers also receive positive feedback.

Negative reviews

When looking at the more critical reviews of the Baxi 400 Combi 2.1, there are some points to consider. Although this model comes in three output sizes, reviewers note that it’s not powerful enough to supply homes with large hot water demands. 

If you have more than 2 bathrooms, for example, this boiler range will struggle to supply water to multiple outlets simultaneously. While combi boilers aren’t typically chosen for larger homes, there are models on the market which offer higher output options.

Some installers have noted that despite the model’s robust brass and stainless steel components, there are more plastic elements used in the overall construction than in some of Baxi’s more premium models. This can impact the boiler’s long-term durability when compared to other designs. 

Some reviewers feel the features offered with the 400 Combi 2.1 are ‘basic’ in comparison to Baxi’s 600 or 800 series. The 400 Combi 2.1 appears to lack some of the high-end functions and premium fittings in comparison. However, these differences are often reflected in the price.

How the Baxi 400 Combi 2.1 compares

To ensure you get the very best boiler for your home, it’s a good idea to compare similar models from different manufacturers. Currently, the top 3 competing models for Baxi’s 400 Combi 2.1 come from Ideal Heating, Vaillant and Worcester Bosch.

To help you get a good overview and compare key functions, we’ve listed the pros and cons for each model below.

Baxi 400 Combi 2.1 Comparison Table
Make and model	Pros	Cons	Average cost (excluding installation)
Baxi 400 Combi 2.1	94% energy efficiency (ErP A-rated) Compact build for easy install Whisper-quiet operation   Long-lasting brass hydraulics and a stainless steel heat exchanger Lower cost and value for money  Baxi scores 4.6/5 on Trustpilot	5-year standard warranty – no options to extend  Output sizes are not suitable for very high hot water demand (24kW, 30kW and 36kW) Features are basic compared to other Baxi series	£770
Ideal Logic Max Combi2	10-year standard parts and labour warranty 94% energy efficiency (ErP A-rated) Compact size Includes system filter Built-in frost protection Ideal scores 4.8/5 on Trustpilot	Occasional issues with customer service Ideal engineers can be slow to respond Fewer output sizes than others (24kW, 30kW and 35kW)	£1,100
Worcester Bosch Greenstar 8000+Combi	Standard warranty of 5 years, extendable to 12 years 94% energy efficiency (ErP A-rated) Sleek design Smart connectivity via Bosch EasyControl Large output range (32kW to 50kW) Worcester Bosch scores 4.6/5 on Trustpilot	Among the more expensive options on the market Dimensions are larger than those of other models (780mm x 440mm x 365mm)	£1,600
Vaillant EcoTec Plus Combi	5-year standard warranty, extendable to 10 years 94% efficiency Wide range of outputs (26kW, 32kW, 36kW, 40kW) Quite Mark Accredited 4.6/5 on Trustpilot	Higher upfront cost than some other brands  Standard warranty is less Larger in size than others (720mm x 440mm x 338mm) Basic display, fewer advanced features	£1,833

Please note that our comparison points do not include every aspect of these models and only offer an overview. Every home is unique, so it’s worth finding the features of your home heating that are most important to you to make a fair comparison. 

To get the very best advice on a boiler model that is suitable for your needs, speak to a Gas Safe registered engineer. 

Final thoughts – is the Baxi 400 Combi 2.1 right for you?

The Baxi 400 Combi 2.1 is a great boiler for small homes looking to reduce their energy consumption and install a hassle-free, reliable heating system.

This model is one of the most competitively priced boilers on the market, at just £740 – £800 (exclusing installation), which also offers high efficiency levels of 94%. That means direct savings on monthly bills and a lower upfront cost than some other brands. 

Baxi is a well-regarded brand with customers and installers, gaining an ‘Excellent’ rating on Trustpilot. Reviews note that the 400 Combi 2.1 is ‘easy to install’ and ‘great value for money’. Its small size and quiet operation also make it great for homes low on space.  

Although this model offers only basic features, it does work with Baxi’s uSense smart thermostat, giving you greater levels of control. The three output sizes in this series are perfect for small and medium-sized homes with up to 2 bathrooms. However, if you have a high hot water demand, you should consider Baxi’s 600 and 800 series for more options. 

While the Baxi 400 Combi 2.1 uses some robust internal components, the 5-year standard warranty is a drawback. There are no current plans which allow users to extend this warranty, making this model slightly less desirable than its competitors (which offer up to 12 years extended warranties). That said, this lower warranty offer is reflected in the bargain price point. 

For competitors, some of the best combi boilers to consider include the Ideal Logic Max Combi², Worcester Bosch Greenstar 8000+ Combi, and Vaillant EcoTec Plus Combi. Each offers different features, designs and output sizes, with varying costs. It’s worth comparing models to find the best for your needs.

If you’re looking for a straightforward, affordable boiler that offers great energy efficiency and reliable performance, the Baxi 400 Combi 2.1 is a great choice. To find the perfect solution for your home, speak to a qualified installer. 

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