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Baxi 600 System

Installed with an unvented cylinder on a fully pumped sealed system, it is perfect for larger properties with several bathrooms or those with a high demand for hot water.

  • Features
  • Dimensions

  • 7 year parts and labour warranty*

  • Built in the UK using top quality brass components

  • Fits inside a standard kitchen cupboard

  • Compatible with market-leading Megaflo Eco cylinder

  • Certified to work with 20% hydrogen

*Terms and Conditions apply.


  • Boiler width [A] = 390mm

  • Boiler height [B] = 700mm

  • Boiler depth [C] = 285mm

  • Side clearance [D] = 5mm*

  • Upper clearance [E] = 178mm*

  • Lower clearance [F] = 200mm*

  • Front clearance [G] = 5mm* in operation, (* 450mm for servicing purposes)


Installer Information

Technical Features

  • Outputs: 15kW, 18kW and 24kW
  • Compact cupboard fit means it can be installed discreetly
  • Lightweight 28kg lift weight
  • Front access to all components saves time when servicing, allowing for ease of maintenance and repair
  • LPG appliances available
  • Certified to work with 20% hydrogen


Baxi 100 Combi

  • Boiler width [A] = 390mm

  • Boiler height [B] = 700mm

  • Boiler depth [C] = 285mm

  • Side clearance [D] = 5mm*

  • Upper clearance [E] = 178mm*

  • Lower clearance [F] = 200mm*

  • Front clearance [G] = 5mm* in operation, (* 450mm for servicing purposes)

Technical Data Table

Baxi 600 System  15 System 18 System  24 System
Sales Code

Boiler only




Controls and accessories

Concealed user controls   No No No
Operating mode selector switch with reset    Yes Yes  Yes
User adjustable DHW temperature  Range - 35°C to 60°C Yes Yes Yes
User adjustable CH temperature   Range - 25°C to 80°C Yes  Yes  Yes
Temp/status/fault diagnosis display    LCD display LCD display LCD display
Wired outdoor weather sensor & relay kit (7683087)   Optional    Optional   Optional  
Baxi wired room thermostat (720971601)   Optional   Optional  Optional 
Baxi twin channel wired programmer (7212443)   Optional  Optional  Optional
Multifit rear pipework kit (7682790)   Optional  Optional   Optional
Pre-plumb jig (7682545)   Optional   Optional  Optional 
ErP Product Information 
Seasonal Space Heating Energy Efficiency % 93 93 93
NOx mg/kWh 29.0 30.0 28.0
Sound Power Level, Indoors  LWA dB 46 48 51
Space Heating Efficiency Class    A
Heat Input CH kW (Max) gross (QnHs) 17.2  20.6 27.4
kW (Min) gross (QnHs)  5.2 5.2 5.2
Heat Output CH (non condensing) factory setting kW (Max) (Pn) 15 18 24
kW (Min) (Pn) 4.5 4.5 4.5
Heat Output CH (condensing) factory setting kW (Max) (Pnc) 16.2 19.4 25.8
kW (Min) (Pnc) 4.9 4.9 4.9
Gas supply connection (mm)  22 22 22
Inlet supply pressure (natural gas)  mbar (nominal)  20 20 20
Maximum Gas Rate (nat Gas after 10 mins)  m3/hr   1.64  1.96 2.61 
SAP 2009 annual efficiency (PCDB/SEDBUK) % 89 89 89
NOx class     6 6
Mechanical and hydraulic  
Heat input central heating (CH)  kW max gross (QnwHs)  17.2  20.6  27.4 
Safety discharge pressure bar  3 3 3
Compartment ventilation required   No No  No 
Flow / return pipe size (mm)  22  22  22
Temporary filling loop supplied    No No No
Integral expansion vessel  Size (litres)  7 7 7
CH system inhibitor required    Yes Yes Yes
Condensate discharge pipe size  (mm)  21.5  21.5  21.5 
Electrical supply   Volts / Hz  230V/50Hz  230V/50Hz   230V/50Hz
Permanent live required     Yes Yes Yes
Electrical cable required core  3 x 0.75  3 x 0.75  3 x 0.75
Power consumption when firing Watts  65 70 100
External fuse rating Amps 
Internal fuse rating - connection board Amps  F2HA250V F2HA250V F2HA250V
Internal fuse rating - Main PCB board  Amps 1.6  1.6 1.6
Boiler IP rating (electrical protection) Approval category   IPX5D  IPX5D  IPX5D 
Circulating pump exercise feature   Yes Yes Yes
Pump overrun     Yes Yes Yes
Integral 'boiler only' frost thermostat    Yes Yes Yes
Concentric flue system 
Standard telescopic concentric flue Length in mm 315-500  315-500  315-500
Horizontal and Vertical concentric (60/100 mm)  Max equivalent length (m)  10  10 10
Reduction per 135° bend (m)  0.5  0.5  0.5
Reduction per 93° bend (m) 
Horizontal and Vertical concentric (80/125mm)  Max equivalent length (m) 20 20 20
Installer lift weight (boiler) Max (kg)  28.1  28.1 28.1
Gross packaged boiler weight  (kg)  30.6 30.6 30.6

Product Training

We offer product training at our training centres across the UK for installers who want to get hands-on with Baxi boilers.

From construction and installation to functions and features, our expert trainers will give you a complete understanding of working with Baxi boilers.

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