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Greenstar 28i Junior

Mother and son with Greenstar boiler in background
Greenstar i Junior boiler

Description

Image of Which 2013 (product pages)

In 2014 and for the fourth year running the entire range of Worcester Greenstar gas boilers have been awarded Which? Best Buy.

With more than 1 million Greenstar i Juniors already installed, the award-winning boiler series is already well-established in the UK.

Compact in size and with domestic hot water outputs of up to 28kW, the Greenstar i Junior is ideal for apartments and small to medium-sized properties with one bathroom.

Image of 5 year guarantee logo (with extra padding)5 year boiler guarantee until 31st December 2014 (terms and conditions apply). See promo page for details.

10 year guarantee on primary heat exchanger and 5 year guarantee on the plate heat exchanger.

Central heating output: 24kW
Domestic hot water flow rate: 11.4 litres per minute at 35 degree temperature rise (provided adequate mains pressure is available)
Designed operational flow rate 10.0 litres per minutes at 40 degree temperature rise.

Efficiency

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Features and benefits

New features and benefits

  • Domestic hot water control added to the boiler fascia, to compliment the central heating control, allowing the homeowner to benefit from increased functionality
  • Now compatible with a full suite of Worcester intelligent and weather compensation controls
  • Switch mode power supply to reduce energy consumption in standby mode by 61%

Established features and benefits

  • A rated efficiency (SEDBUK 2005 value)
  • 2 year guarantee, 10 year guarantee on primary heat exchanger and 5 year anti-scale guarantee on domestic hot water heat exchanger (subject to terms and conditions)
  • Compact dimensions – space saving, siting flexibility and a class-leading lift weight of 26kg
  • Ability to pre-plumb all 7 connections without the boiler being on the wall – gas, water, PRV & condensate connections. Robust wall mounting frame provided as standard allows space for pipes behind the boiler
  • Full range of Condensfit II horizontal and vertical flue options with optional plume management kit available

Technical data table

Technical data
Title Value
Ingress protection (IP) X4D
NOx classification with low NOx code plug (mg/kWh) 38
NOx classifications (mg/kWh) 66
Height (mm) 710mm (max)
Width (mm) 400mm
Depth (mm) 330mm (max)
Weight 27.1kg
SEDBUK value %/band - LPG 91.8%/Band A
SEDBUK value %/band - natural gas 90.1%/Band A
DHW flow rate @ 35°C rise 11.4 l/min
Output to central heating 7.2 - 24kW (24,566 - 82,000Btu/hr)
Solar compatible No
Maximum horizontal flue (100mm Ø) 4,600mm (inc. terminal)
Maximum vertical flue (100mm Ø) 6,400mm (inc. terminal)
Maximum horizontal flue (125mm Ø) 13,000mm (inc terminal)
Maximum vertical flue (125mm Ø) 15,000mm (inc. terminal)
Mains cold water inlet 15mm compression
Domestic hot water outlet 15mm compression
Gas connection 22mm compression
Pressure relief valve 15mm
Heating flow and return connections 22mm compression
Condensate connection 22mm plastic pipe
Maximum domestic water inlet pressure 10bar
Minimum domestic water inlet pressure for maximum DHW rate 1.3bar
Minimum domestic water inlet pressure to operate the appliance 0.2bar
Primary water content 3.9 litres
NOx class Class 5
Wall mounting jig Yes
Filling link Optional
Plug-in timers Yes (optional)
Optimising room temperature controller Yes (optional)
Condensing in DHW mode No

Literature

Product guides and brochures
Title/description Part number Order
Greenstar gas boilers brochure

Greenstar gas-fired condensing boilers from Worcester. Making a positive difference to your life, your fuel bills and the environment.

8 716 109 642

download icon Download (3.16 MB)

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Product guide for gas boilers and solar heating 8 716 116 713

download icon Download (2.76 MB)

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Product literature
Title/description Part number Order
Benchmark Commissioning Checklist effective from 1st April 2014 6 720 810 989

download icon Download (0.29 MB)

Installation manual for Greenstar i Junior (manufactured from Jul 13) 6 720 802 047

download icon Download (22.91 MB)

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Tech and spec for wall mounted gas combi boilers 8 716 116 716

download icon Download (12.90 MB)

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User manual for Greenstar i Junior (manufactured from Jul 13) 6 720 802 048

download icon Download (1.67 MB)

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Accessory literature
Title/description Part number Order
CondenseSure brochure 8 716 116 559

download icon Download (1.11 MB)

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CondenseSure Siphon - Installation instructions 6 720 803 103

download icon Download (2.19 MB)

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DT20RF Digital RF thermostat with twin channel programmer (MK 2) instructions 8 716 115 495

download icon Download (4.40 MB)

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Expansion vessel hose and syphon assembly 8 716 113 893

download icon Download (0.91 MB)

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Installation and Service Instruction Cross Bonding Strip Greenstar WM Gas (Issue Apr 10) 6 720 642 632

download icon Download (0.14 MB)

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Installation and Service Instruction Filling Link (Issue A May 02) 8 716 105 080

download icon Download (0.10 MB)

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Installation and Service Instruction Greenstar SL i Junior low nox conversion (Issue 2009/10) 6 720 645 755

download icon Download (1.16 MB)

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Installation Instructions for Greenstar System Filter 6 720 803 839

download icon Download (2.12 MB)

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Integral charging link fitting and user instructions 8 716 114 661

download icon Download (0.54 MB)

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Keyless Filling Link Brochure 8 716 116 753

download icon Download (0.97 MB)

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MT10 instructions 8 716 106 641

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MT10RF user instructions (MK II models from Aug 09) 8 716 115 752

download icon Download (1.87 MB)

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Operation Instruction DT10RF Mk2 V1 Digistat (Issue A Aug 07) 8 716 114 477

download icon Download (9.34 MB)

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Quick start guide for MT10RF 8 716 115 007

download icon Download (0.33 MB)

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Tech and spec for heating controls 8 716 115 653

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Vertical pre-piping assembly fitting instructions (Issue C Oct 09) 8 718 681 432

download icon Download (0.23 MB)

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Worcester Greenstar System Filter brochure

Brochure for the Worcester Greenstar System Filter accessory

8 716 116 618

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Flue literature
Title/description Part number Order
60/100mm horizontal flue instruction manual 6 720 644 842

download icon Download (5.64 MB)

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60/100mm Vertical flue kit instructions 6 720 611 739

download icon Download (0.41 MB)

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80/125mm 45° flue duct kit instructions 6 720 641 098

download icon Download (0.18 MB)

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80/125mm 90° flue duct kit instructions 6 720 641 097

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80/125mm flue extension kit instructions 6 720 641 099

download icon Download (0.14 MB)

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80/125mm horizontal flue instructions (Issue June 09) 6 720 611 436

download icon Download (0.31 MB)

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80/125mm vertical flue kit instructions (Issue Sept 09) 6 720 611 740

download icon Download (0.40 MB)

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Installation and Service instruction Condensfit 2 100mm flue extension (Issue Dec 08) 6 720 617 795

download icon Download (0.16 MB)

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Controls literature
Title/description Part number Order
DT10RF Digistat (MK 2) instructions 8 716 115 493

download icon Download (4.24 MB)

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DT20 Twin Channel Digital Timer user instructions (Issue B Nov 04) 8 716 106 647

download icon Download (1.91 MB)

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MT10RF mechanical RF thermostat instruction manual (Issue d Dec 06) 8 716 107 486

download icon Download (1.31 MB)

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Operation Instruction DT10RF Mk1 V1 Digistat Optimiser (Issue A Aug 07) 8 716 114 492

download icon Download (1.44 MB)

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Operation Instruction DT20RF Mk2 V1 Digistat (Issue A Aug 07) 8 716 114 478

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Wave smart control operating and installation guide 6 720 810 446

download icon Download (3.88 MB)

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Wave technical sales brochure 8 716 117 624

download icon Download (1.80 MB)

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Hydraulic schematic diagrams
Title/description Part number Order
Hydraulic schematic hybrid plus with combi, radiator and underfloor heating AHC0120a

download icon Download (5.20 MB)

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