Baxi 600 System 2

The Baxi 600 System 2 boiler is the perfect option when you need lots of hot water or have more than one bathroom.

It is compatible with Baxi cylinders and the Megaflo Eco range and comes with a seven-year parts and labour warranty*.

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*Terms and conditions apply

Baxi 600 System 2
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Features and benefits   |   Dimensions   |   Product literature   |   Technical specifications   |   Related products   |   FAQs

Features and benefits


  • 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)
Baxi 600 System 2 Line Diagram_ALT
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Product literature

Technical specifications

  • 15, 18 & 24kW System (Natural Gas or LPG)
  • Compact cupboard fit
  • Brass hydraulics block
  • Built-in stand-off frame
  • Certified OpenTherm
  • Simple hanging bracket
  • Vertical sleeve recyclable packaging
  • Combined PrV with seperate drain
  • Colour-coded and removable wiring blocks
  • Pre-heated siphonic condensate trap
  • Easy-fill 2 permanent filling link


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Technical Table   Baxi 615 System 2 Baxi 618 System 2 Baxi 624 System 2
Sales Code   7798687 7802020 7802241
Natural gas or LPG   Yes Yes Yes
Inlet supply pressure (natural gas) mbar (nominal) 20 20 20
Maximum Gas Rate (G20) Qmax m³ / hr 1.64 1.97 2.61
Heat Input CH kW (max) Gross (QnHs)  15.5 18.6 24.7
  kW (min) Gross (QnHs) 4.9 4.9 4.9
Heat Output CH (non-condensing) kW (Max) (Pn) 15 18 24
  kW (Min) (Pn) 4.8 4.8 4.8
Heat Output CH (condensing) kW (Max) (Pnc) 16.3 19.9 26.3
  kW (Min) (Pnc) 5.2 5.2 5.2
Heat Input domestic hot water (DHW) kW max gross (OnwHs)  N/A N/A N/A
Heat Output domestic hot water (DHW) kW max  N/A N/A N/A
Water heating efficiency class   A A
Permanent live required   Yes  Yes  Yes 
External fuse rating (on connection board) Amps F0.5A L250VP F0.5A L250VP F0.5A L250VP
Pump overrun   Yes Yes Yes
Integral 'boiler only' frost thermostat   Yes Yes Yes
Maximum DHW flow rate (Delta T @35'C rise)  l/min N/A N/A N/A
Minimum DHW flow rate required   l/min 
Minimum operating DHW pressure required bar 0.5  0.5  0.5 
Integral expansion vessel Size (litres) 
Maximum capacity of the CH system Litres  100  100  100 
Integral automatic bypass   Yes  Yes  Yes 
Installer Lift Weight (kg) 28  29  30 

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Looking for an installer near you to advise you on your new heating system? Simply enter your postcode and find a local, trained, Gas Safe registered engineer to give you a free, no-obligation quote on a new boiler, cylinder, service or repair.

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More information


  • How to reset a Baxi boiler
  • How do I bleed a radiator?
  • How to recharge the air gap on a Megaflo unvented cylinder
  • What happens at boiler service? 
  • General warranty information

Read how to reset your boiler, whether it has a dedicated reset button, an ON/OFF/SELECTOR switch or a thermostat control knob.

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If you have cold spots at the top of your radiators, it means that there is trapped air that needs to be removed so your radiators will heat your room efficiently. Follow our simple steps for bleeding your radiators.

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If you've noticed that water is dripping from the safety pipe outside or through the tundish on the outside of your cylinder, this is an indication that the air gap in your cylinder needs recharging. Watch our video to find out how you can easily fix this yourself, without calling a heating engineer.

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Getting your boiler serviced every year is a bit like getting your car serviced. The law requires that all servicing and gas safety checks are made by a Gas Safe registered engineer and an annual service can make all the difference in reliability, efficiency and household bills. If your boiler is still under warranty, having an annual service is a condition of the warranty. Always ask to see the engineer's Gas Safe ID.

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We explain how long your Baxi boiler warranty is, what it covers and whether it is transferrable. 

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