Baxi 400 Combi LPG

The Baxi 400 Combi LPG is a high efficiency boiler; simple to use and provides plenty of heating and hot water, whenever you need it.

Available in a 28kW output, the boiler is compact and small enough to fit in a kitchen cupboard and has a rigid filling loop that is easy to use and discreetly hidden out of sight, perfect for most properties. It has the option to be operated using a smart phone or tablet and the reliable Baxi technology is backed by a five year parts and labour warranty* for extra peace of mind.

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  • Available in a 28kw output to suit most homes
  • Compact size that can be installed in a 290mm deep cupboard
  • 26kg lift weight making it easy to transport, unpack and install
  • Includes the option to be operated using a smartphone or tablet
  • Modular fan gas air unit for easy maintenance
  • Rigid filling loop for a neater finish
  • Optional stand off frame for neater installations for hidden pipework
  • Industry leading choice of flue lengths, bends and accessories for versatile sitting and easy replacement
  • Vertical packaging for ease of transport and unpacking
  • 5 year warranty as standard*

*Subject to registration and an annual service. Terms and conditions apply. Visit


A: Boiler width = 395mm

B: Boiler height = 700mm

C: Boiler depth = 279mm

D: Side clearance = 5mm

E: Upper clearance = 178mm

F: Lower clearance = 200mm

G: Front clearance = 6mm in operation, 450mm for servicing

Baxi 400 Combi LPG 28 Combi LPG
Sales Code

Boiler only



Concealed User Controls No
Operating mode selector switch with reset Yes
User adjustable DHW temperature Range - 35° to 60° (±5ºC) Yes
User adjustable CH temperature Range - 25° to 80° (±5ºC) Yes
Temp/status/fault diagnosis display LCD display
Integral 24 hr electro-mechanical timer (247206) Optional
Plug-in 24 hr mechanical timer combi (7658276) Optional
Plug-in 7 day digital timer combi (7658523) Optional
 Plug-in receiver 24 hr RF programmable mechanical room thermostat-combi (7658781)   Optional
Plug-in receiver 7 day RF digital programmable mechanical room thermostat-combi (7658789) Optional
Single channel 7 day wired programmable room thermostat-combi (7212438) Optional
Single channel wired timer (7212444) Optional
Room thermostat (720971601) Optional
Baxi 200 and 400 stand off kit (7659335) Optional
SAP 2009 annual efficiency (PCDB / SEDBUK) % 89
NOx class 5
ErP Product Information
NOx mg/kWh 40
Sound Power Level, Indoors LWA dB 50
Space Heating Efficiency Class A
Water Heating Declared Load Profile XL
Water Heating Efficiency Class A
Heat Input CH kW max gross (QnHs) 27.42
kW min gross (QnHs) 5.44
Heat Output CH (non condensing) factory setting kW (Pn) 20
kW (Pn) 4.8
Heat Output CH (condensing) factory setting kW max (PnC) 21.8
kW min (PnC) 5.2
Gas supply pipe size (mm) 22
Inlet supply pressure (natural gas) mbar (nominal) 20
Maximum gas rate (natural gas after 10 mins) m3/hr 3.06
Mechanical and hydraulic
Heat input domestic hot water (DHW) kW max gross (QnwHs) 32.1
Heat output domestic hot water kW max 28
Maximum DHW flow rate (Delta T @ 35ºC max) l/min 11.5
Minimum DHW flow rate required l/min 2
Minimum operating DHW pressure required bar 0.15
Maximum DHW system pressure bar 8
Safety discharge pressure bar 3
Compartment ventilation required No
Flow / return pipe size (mm) 22
Filling loop supplied Yes
Integral expansion vessel Size (litres) 7
CH system inhibitor required Yes
Condensate discharge pipe size (mm) 21.5
Electrical supply Volts/Hz 230V/50Hz
Permanent live required Yes
Electrical power cable required core 3 x 0.75
Power consumption when firing Watts 94
External fuse rating Amps 3
Internal fuse rating - Connection board Amps 0.5
Internal fuse rating - Main PCB board Amps 1.6
Boiler IP rating (electrical protection) without integral timer fitted Approval category IPX5D
Circulating pump exercise feature Yes
Pump overrun Yes
Integral 'boiler only' frost thermostat Yes
Concentric flue system
Standard telescopic concentric flue Length in mm 315-500
Horizontal concentric (60/100 mm) Max equivalent length (m) 10
Reduction per 135° bend (m) 0.5
Reduction per 93° bend (m) 1
Horizontal concentric (80/125mm) Max equivalent length 20
Installer lift weight (boiler) Max (kg) 26
Gross packaged boiler weight (kg) 30.5


Additional heating and hot water accessories can improve the overall efficiency and performance of your heating system. This could reduce your fuel consumption and your energy bills.

For more information on any of the below accessories please speak to your installer as they will be able to advise you on the controls that are right for you.

  • Baxi plug-In 24 hour single channel mechanical timer
  • Baxi plug-In 7 day single channel digital timer
  • Baxi plug-In receiver 24 hour single channel programmable mechanical room thermostat
  • Baxi plug-In receiver 7 day RF digital single channel programmable room thermostat
  • Baxi single channel wired programmable room thermostat
  • Baxi single channel wired timer
  • Baxi combi wireless 7 day programmable room stat
  • Baxi room thermostat

For more information on the Baxi 400 Combi LPG accessories, click here

You can download product information on the Baxi 400 Combi LPG here:

  • Baxi 200 & 400 Range Guide (PDF 3.60MB, 11/09/2017)
  • Baxi 400 Combi LPG Consumer Guide (PDF 0.62MB, 29/08/2017)
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