Greenstar i System (9kW to 24kW) overview

Our Greenstar i System is our most popular wall-mounted system boiler with outputs up to 24kW.

Suitable for a wide range of homes, this boiler comes with a steel wall-mounting jig that not only allows pipes to go behind the boiler but also the ability to pre-pipe all of the pipework before the boiler is placed on the wall.

The appliance can be used with our range of high efficiency Greenstore cylinders.

Greenstar i System (9kW to 24kW) Greenstar i System (9kW to 24kW) Greenstar i System (9kW to 24kW)
Greenstar i System (9kW to 24kW) Greenstar i System (9kW to 24kW) Greenstar i System (9kW to 24kW)

Features & Benefits

Wall mounting jig providing pre-plumbing and rear piping as standard
Low lift weight
Single panel front for ease of removal
Central heating flow temperatures can be adjusted using simple up/down button
Plug & play optional Worcester controls available*
Fan can be removed with just one screw and the expansion tank is now inside the boiler
Large siphon inside - eliminates risk of condensate pipe freezing**
Achieves an A+ ErP efficiency rating for heating when installed with a Wave smart internet connected control (Excludes 9kW variant)
Simple boiler controls with clear information display
Commissiong information for easier completion of the Benchmark checklist
Homeowner service reminder
Homeowner service reminder
Scan and register the boiler using our FREE online registration app

Technical Details

Greenstar 9i System Greenstar 12i System Greenstar 15i System Greenstar 18i System Greenstar 21i System Greenstar 24i System
Part number 7 733 600 011 7 733 600 010 7 733 600 009 7 733 600 008 7 733 600 007 7 733 600 006
ErP Efficiency Rating
A
A
A
A
A
A
Solar Compatible
Wave Compatible *
Control Options
Dimensions (mm) height x width x depth 710 x 400 x 330 710 x 400 x 330 710 x 400 x 330 710 x 400 x 330 710 x 400 x 330 710 x 400 x 330
Clearances (mm) above, sides, below and front 30, 5, 200, 600 30, 5, 200, 600 30, 5, 200, 600 30, 5, 200, 600 30, 5, 200, 600 30, 5, 200, 600
Maximum horizontal flue (mm) 4600 4600 4600 4600 4600 4600
Maximum vertical flue (mm) 6400 6400 6400 6400 6400 6400
Ingress protection rating IP20 IP20 IP20 IP20 IP20 IP20
Wall mounting jig supplied
Central heating output (kW) 9 12 15 18 21 24
Minimum inlet pressure (bar) N/A N/A N/A N/A N/A N/A
NOx emissions (mg/kWh) 36 45 42 50 49 49
Lift weight (kg) 30.9 30.9 30.9 30.9 30.9 30.9

*With installation of optional built-in diverter valve

**The Condensesure Siphon has been proven to be effective at preventing frozen condensate at -15°C for a sustained period of 48 hours. 32mm pipework must be used and should not exceed 3 metre

Frequently Asked Questions

Question
Can I use artificially softened water in the heating circuit with my boiler?
Can Worcester products be used with underfloor heating?
What ventilation do I need?
Do you recommend treatment of the central heating water?
How does part L of the Building Regulations affect my boiler installation?
What is ErP?
What is Energy Labelling?
How will ErP affect me and my business?
How will ErP benefit me and my business?
Under ErP, what about systems that contain different products?
How do controls affect ErP?
As an installer, am I required to print the efficiency label? Or am I required to make a label and send it out?
Can you advise where to find and learn more on how to calculate and provide an ErP label?
What if I install a system with a programmer or other non-Worcester components? Will I still be able to use the Worcester ErP online tool?
Why is it necessary when we already have an appliance label and a home Energy Performance Certificate both of which are based on the well understood A-G scale?
Which programmers are compatible with my gas boiler?
Can I put flue elbows straight on top of the boiler?
Do I need a standoff kit to pipe up the back of your boilers?
Why is the boiler blowing fuses?
Why is the pump running constantly on a Greenstar CDi boiler?
Where can I find the FD (serial) number on a Greenstar boiler?
Can I fit your controls to an external oil boiler?
Can I run boiler flues outside?
Does an external condensate pipe have to be insulated?
Can I use third party controls with your boilers?
Which connector block do I use on a Greenstar boiler when wiring a Wave smart internet connected controller?
Can I use Worcester controls with a system boiler?
Find answer to more frequently asked questions

Related Accessories

Boiler Accessories Part number
Greenstar System Filter
Greenstar System Filter 7 716 192 609
ISM1 Intelligent Solar Module
ISM1 Intelligent Solar Module 7 716 192 068
Greenstar Comfort wall mounting plate
Greenstar Comfort wall mounting plate 7 733 600 039
Condensesure
Condensesure 7 716 192 746
Earth bonding strip
Earth bonding strip 7 716 192 686
Below boiler pipe cover
Below boiler pipe cover 7 716 192 608
Remote pressure relief valve kit
Remote pressure relief valve kit 7 716 161 071
Optional 18kW diverter valve kit
Optional 18kW diverter valve kit 7 716 192 568
Greenstar i System ErP internal diverter valve kit
Greenstar i System ErP internal diverter valve kit 7 733 600 089
Optional 12kW diverter valve kit
Optional 12kW diverter valve kit 7 716 192 566
Optional 24kW diverter valve kit
Optional 24kW diverter valve kit 7 716 192 409
Heat exchanger cleaning kit
Heat exchanger cleaning kit 7 733 600 091
Optional 15kW diverter valve kit
Optional 15kW diverter valve kit 7 716 192 567
Flashing Kits Part number
Pitched roof flashing kit (100mm & 125mm dia)
Pitched roof flashing kit (100mm & 125mm dia) 7 716 191 091
Flat roof flashing kit (100mm & 125mm dia.)
Flat roof flashing kit (100mm & 125mm dia.) 7 716 191 090
Flue Part number
45 degree bend (100mm dia.)
45 degree bend (100mm dia.) 7 719 003 665
1000mm extension (125mm dia.)
1000mm extension (125mm dia.) 7 719 003 666
Horizontal flue kit (125mm dia.)
Horizontal flue kit (125mm dia.) 7 719 003 702
Support bracket kit 6 pack (100mm dia.)
Support bracket kit 6 pack (100mm dia.) 7 716 191 173
90º bend (125mm dia.)
90º bend (125mm dia.) 7 719 003 664
Long telescopic flue kit (100mm dia.)
Long telescopic flue kit (100mm dia.) 7 716 191 171
High level horizontal telescopic 60/100mm flue kit
High level horizontal telescopic 60/100mm flue kit 7 733 600 048
Support bracket 6 pack (100mm dia.)
Support bracket 6 pack (100mm dia.) 7 716 191 178
Support bracket (125mm dia.)
Support bracket (125mm dia.) 7 716 191 179
Support bracket kit (100mm dia.)
Support bracket kit (100mm dia.) 7 716 191 177
Support bracket kit (125mm dia.)
Support bracket kit (125mm dia.) 7 716 191 174
90º elbow 60/100
90º elbow 60/100 7 719 002 348
Short flue extension, 220mm (100mm dia)
Short flue extension, 220mm (100mm dia) 7 716 191 133
Support bracket kit (100mm dia)
Support bracket kit (100mm dia) 7 716 191 092
90º bend (100mm dia.)
90º bend (100mm dia.) 7 716 191 084
1000mm extension kit (100mm dia.)
1000mm extension kit (100mm dia.) 7 716 191 083
2m flue extension (100mm dia.)
2m flue extension (100mm dia.) 7 716 191 172
High level horizontal flue adaptor (100mm dia)
High level horizontal flue adaptor (100mm dia) 7 719 002 432
60/100mm (x2) 45º bends
60/100mm (x2) 45º bends 7 716 191 085
Vertical BF kit (125mm)
Vertical BF kit (125mm) 7 719 002 431
Vertical BF kit (100mm)
Vertical BF kit (100mm) 7 719 002 430
High level horizontal flue adaptor (125mm dia)
High level horizontal flue adaptor (125mm dia) 7 719 002 433
Standard telescopic horizontal flue kit (100mm dia)
Standard telescopic horizontal flue kit (100mm dia) 7 716 191 082
Other Part number
Security fixing kit
Security fixing kit 7 716 192 261
Plume Part number
Plume management kit (60mm dia)
Plume management kit (60mm dia) 7 716 191 086
Plume management terminal guard round (60mm dia.)
Plume management terminal guard round (60mm dia.) 7 716 191 176
90º bend
90º bend 7 716 191 088
45º bend (x2)
45º bend (x2) 7 716 191 089

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