Baxi 400 Combi 2.1

Baxi 400 Combi 2.1 Boiler

Combi Boilers

Baxi 400 Combi 2.1

Extremely quiet, compact and lightweight, the Baxi 400 Combi 2.1 boiler can be installed virtually anywhere in your home.

Features and Benefits

Warranty

5-year parts and labour warranty for peace of mind†

    Fuel types 

    Works with natural gas or LPG, without a conversion kit

      Ready for winter

      Pre-heated condensate trap to help prevent freezing in winter – less risk of frozen condensate pipes!

        Pressure gauge

        External analogue pressure gauge for easy self-top up, reducing the need for engineer call outs

          Smart thermostat

          Compatible with Baxi uSense smart thermostat, which you can control using an app on your phone
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            Product Literature

            User Guides

            User Guides

            Product Documentation

            No documentation available.

            Installation & Service Manuals

            Installation & Service Manuals

            Product Documentation

            No documentation available.

            Energy Labels

            Energy Labels

            Product Documentation

            No documentation available.

            Baxi 400 Combi 2.1 Boiler Dimensions

            Dimensions

            A: Boiler width = 395mm

            B: Boiler height = 700mm

            C: Boiler depth = 285mm

            D: Side clearance = 2.5mm

            E: Upper clearance = 178mm

            F: Lower clearance = 150mm

            G: Front clearance = 5mm in operation (450mm for servicing)

            Related FAQs

            Should I turn off my boiler in the summer?

            In Summer, you might be tempted to switch off your boiler to save money. However, this can be inefficient and expensive. Instead, you should consider setting your boiler to only heat your water.

            What is the Boiler Upgrade Scheme?

            The Boiler Upgrade Scheme is a Government grant of £7,500 to support with the upfront costs of installing low carbon heating systems, such as an air source heat pump, subject to eligibility. A temporary uplift of £1,500 was also introduced in July 2026 to provide additional support for off-grid property owners.

            Does my boiler filter need cleaning?

            Your filter should be cleaned during your boiler’s annual service. This will prevent sludge building up in your system. Some filters come with an app that can warn you when they filter needs to be cleaned, so that you can arrange for your installer to visit before it gets too full.

            What is central heating sludge?

            Central heating sludge is a substance that builds up in central heating pipes as a result of rusted and dissolved metal settling in the system.

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            Related Products

            Save £7,500 with the Boiler Upgrade Scheme

            If you are upgrading your heating system, have you considered installing an air source heat pump? Right now, you could be eligible for a grant of £7,500 to help with the installation cost.

            Book a service

            Help keep your heating working as it should with a Baxi service. We offer servicing for boilers, filters, cylinders, air source heat pumps and more.

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