The Best Buyers Guide -Worcester Bosch Greenstar I Junior Combi | Price & Reviews

Boilers have become an advanced source of comfort to rising needs of warmth, health, and care. They ensure our homes against the icy cold weather and provide solace. It turns out that the rising industry and competition in the market have created an expanded demand for a better and cost-effective boiler of the latest generation. A boiler comes with features that explicitly depict the efficiency of its system. The brands available out today at times prove a disappointment, whereas some seem to excel in their field of innovation.

The more advanced we get, more options of advancement that approach us. It is quite difficult and  an extremely weary task to choose from amongst a list containing more than 10 brands and beyond 100 variants under each type.

Reliability, Quality, Efficiency and Productivity are few factors that stir the customer to buy a particular boiler. And with no further doubt, Worcester Bosch has produced itself as one of the main most leading brands that has reached a peak of reputation gained over the years of experience, for liberating the most innovative devices for its consumers over the decades.

Worcester Bosch has never once failed to recognise the needs of its user and abide strictly to meeting the requirements with ease and comfort for usage.

Worcester Bosch has gained the fame of Quality and Reliability with the strength of its products. The brand of boilers comes with different types of boilers ranging from :

Regular boiler to Combi boilers including System Boilers

With our deepest research and survey we have conclusively found out, 80% of people prefer Combi boilers. The reason varies to individual, yet the most common reasons vary between :

  1. The efficiency of the boiler just as much the traditional boiler system could handle.
  2. The compact size of the boiler that made it easy fit, easy install and beyond all has not compromised with the huge body operations which were once carried out using huger systems.
  3. The affordability that makes it more attractive to various classes of people.
  4. The different ranges of output available to the system as per the size of the apartment and requirement.
  5. The exclusion of cylinders that reduce the over consumption of space and reduces the risk of an extra fitted cylinder.
  6. The ease of control with the help of remote control or app control system etc.

Worcester Bosch through its Greenstar I Junior Combi model, serves dual purpose! As the name suggests, it is a pure combination of water heating as well as central heating for your homes! Thus ensuring that Resource, Energy, Space and Cost are effectively managed for a more sustained environment.

Here we have Introduced, discussed, compared, and reviewed the two variants under, Worcester Bosch Greenstar I Junior Combi Boiler.

  1. Worcester Bosch Greenstar 24I Junior Combi
  2. Worcester Bosch Greenstar 28I Junior Combi

Worcester Bosch Greenstar I Junior Combi  :   

          The Worcester Bosch Greenstar I Junior Combi model boiler was specifically made to suit small and cozy apartments or homes that consist of lesser no. Of regulators and 1 bathroom. These were technically designed to suit the smaller spaces thus making it look much compact and comfortable to use.

ModelOur RatingAvailability Price Customer Rating
24I5.6/10Discontinued£767.392.8 out of 5 Global ratings
28I6.2/10Discontinued£854.883.1 out of 5 Global ratings

Worcester Bosch Greenstar 24I Junior Combi

An effortlessly superior brand by its looks, charms and affordability that enriches its features and makes it available to men of any class to have their source of comfort at home. One of the most sustainable operations through its special features that make it work apart from the competition rival boilers out in the market.

The brand has attained a peak of reputation which is synonymous with Reliability and Quality.  Hence it has never failed to please its customers. Junior Combi Boilers is specially designed for modern apartments and small to medium-sized properties with one bathroom. It comes quite picky with a compact design and multi-directional flue which provides extra flexibility.  High performance with high fuel efficiency is the significant factor to notice among the points that make 24I junior Combi noteworthy.



  • User friendly
  • Easy Control
  • Compact
  • Low energy consumption
  • Low gas bills
  • Higher productivity
  • Cost efficient
  • Load and Weather compensation through control
  • Long duration warranty ( upto 12 years )
  • Higher output
  • Reduced Electrical usage by 30%
  • Easy installation
  • Digital app control
  • Frost free


  • Higher maintenance
  • Repair works are difficult and complex
  • Ease of servicing is considerably low
  • No backup immersion heater installed. So in the event of a breakdown, you won’t be able to heat your water.


  • Simple boiler controls with clear information display
  • Condensate discharge resilient to freezing up to -15’C* **
  • Wide choice of controls enables greater comfort and economy
  • Low energy pump reduces electrical usage
  • Hot water instantly heated from cold mains
  • Achieves an A+ ErP package efficiency rating for heating when installed with a smart internet-connected Bosch EasyControl
  • High energy efficiency
  • NOx Class 5- Low NOx and CO2 emissions  Environmentally friendly
  • Compatible with Worcester’s simple mechanical timers and most of their digital programmers and room thermostats.   
  • User comfort Energy efficiency Economy
  • Comes with a central heating control.      
  • User Comfort
  • Featuring Worcester keep-hot facility for instant hot water.
  • Convenience
  • Compatible with Greenskies solar panels.       Alternative energy option
  • Compact dimensions with multi-directional fluing.
  • Siting flexibility
  • Wall mounting frame with no exposed pipework   
  • Easy installation


  • Dimensions:

H – 710 mm W – 400 mm  D – 330 mm

  • Output : 24kW/28kW
  • Standard Warranty      7 Years
  • Band Rating        B Rated
  • Efficiency: 89.10%

The Worcester Bosch Greenstar i junior Combi comes under 2 variant forms as listed above.

The 24 kW and 28kW boilers have slight differences that offer varied flow rate, varied output and hence the difference in price.

For more detailed information we have compared the two below : 

Model Greenstar 24i Junior Combi Gas BoilerGreenstar 28i Junior Combi Gas Boiler
Central heating O/p24kW 28kW
Flow rate11 l/m13 l/m


Picking the right and most appropriate boiler from the wide varieties of models available in the market is quite a daunting task. The model, brand and price alone does not provide the basic information required to decide on the perfect boiler for your home. Choosing the right one is equally significant to ensure safety.

Safety tied to any electrical device comes at a greater expense. The quality and reliability of a brand must be more vibrant than any of its contrasting features. 

    We have jot down the valid requisites to look out for, while purchasing a boiler for your home :

  • The size of your home space available and the size of your boiler.

The Size of your home decides the size of the boiler. Lesser the number of rooms and bathrooms, lower the required heating capacity.Choosing the right size includes two major factors:

  • Heating capabilities
  • Whether the physical size would fit your home space.

It would always be best to obtain further information and advice from an engineer regarding the heating efficiency required for your home and its installation.

The use of smaller boilers for a vaster home would only provide evident inefficiency. And the vice versa usage of larger boilers for limited home spaces would lead to increased bills, increased heating of limited heating sources. Which could in adverse be dangerous.

  • Compact but efficient as much as the Classic boilers.

Reduced size does not mean reduced efficiency. No compromise is appreciated when it comes to efficiency with regard to the reduced size.

  • Cost efficient and resourceful

The most highlighting feature as compared to boilers since decades is that modern boilers are resourceful and consume less electricity. They do not come with pocket tearing bills at the end of the month. The price is affordable and much advantageous since it comes with a long guarantee upto 7 to 10 years.

  • Gas boilers

Choosing an efficient boiler also means moving ahead with time and advancement.  It would be appropriate to use the technically advanced method of heating than to stick with the older methods that could prove fatal or damaging to homes. Gas seems neater and more cost effective. The modern Gas condensing boilers result in a decent energy bill and higher returns of savings on resources.

Based on an efficiency test calculated with respect to an industry standard, called SAP 2009, the least efficient has a rating of 88.2 and the most efficient amongst the Alpha E Tec system boiler ranges upto 93%.

  • ErP rating

Higher the ErP, safer and cleaner the option. As the rating increases the ability of the device to function increases but at the same time the resource consumption decreases and the savings on energy and electricity decreases with high effectiveness.

  • Controls and safety apparatus.

Make sure the boiler you prefer to purchase is advanced enough to incorporate reliable safety measures, safety controls and offers precautionary measures. The device should be manufactured with utmost precision, hence the reliability of a famous brand like Worcester allows you to settle in peace. The machine should consist of good quality materials that do not fuse, melt or radiate tremendously due to high heating. The combi boilers usually come in ON and OFF mechanism that only works as per our requirement. Thus we are able to control the operation manually. The operational device shall be well suited to easy handling and controlling.

  • Lower complexity

The easy functioning and operating of devices makes it easier to handle.

The technicalities to be kept on the comprehensible side of the user is quite a  task for the manufacturers. To which the Vokera has justified itself.

  • Varied ranges.

One’s size of home and the size of device is always interlinked and helps produce the best results always.

The size is what determines the outcome and the output efficiency.  The Vokera range offers almost 13 to 15 models simply under the combi model and even a better range under the other categories. Which makes the process of choosing quite daunting yet offers a wider range to choose from.


Worcester Bosch and its products are the popular and practical choices of the people who trust in the quality and rely on the efficiency of the brand and its products ever since the start. The company has earned a reputation over the last decades in its field of excellence in innovation, ease of operation, advanced features, customised compact designs and the production of top quality heating systems.

The industry influencers on a recent survey conducted have conclusively arrived at the fact that Popular fame of the brand is much due to reliability and productivity it has served over the years. Around 63% of families who seek to purchase a new boiler for their homes do a thorough research and end up buying the No.1 brand due to the ratings, which is ultimately Worcester Bosch.

Ranging from 12 to 20 radiators, single bathrooms to multiple bathrooms and central heating to a limited flat to a vast and spacious apartment can be nurtured out using the Worcester Bosch and its boiler products. The device has a user-friendly display, beneath the flap, making the boiler relatively easy to operate. There you will find a clear temperature display, buttons to increase or reduce heat and options to set modes, such as pre-heating.

The Worcester Bosch product comes with an ErP of 92% and an A rating that does its half for the environment as well.

The brand is thus one of the most reliable and trustworthy companies that offer the most efficient boilers of today’s generation. Yet, the Worcester Bosch Greenstar i junior Combi seems to have default incapabilities in few areas which the manufacturers have given importance, due to which the model is no longer available and has been replaced by more productive and innovative models.



Efficiency – 85%

Ease of use – 90%

Quality – 95%

Resourceful and cost effective – 99%

Worcester Bosch has never failed to satisfy the human wants and in fact have earned a class reputation over the decades of service. Worcester has turned out as a casual and household name in the UK, since the beginning of time. Quality and reliability are the key features aimed at by the Worcester Bosch. The brand signifies its importance through the safety and sustainability provisions of the brand and its products. Our reliability on the brand is in due relation to the customer reviews and satisfaction the company has earned. Efficiency, Durability, Sustainability are uncompromised to any extent.

Other features we have observed also include:

  • SEDBUK A rating of 90.5% (2005 value)
  • Reduction in raw materials due to the precise engineering of the WB7
  • All components are 100% recyclable
  • Low electrical standby consumption



  1. Name :  J. B Foxall

Date of purchase : 13 November 2013

Item bought : Greenstar 24i junior Combi

Rating: 5/5


Had our Worcester boiler installed after years of struggling with the 15 year old appliance originally fitted when the house was built. Wow, what a difference. The boiler is so quiet it’s almost uncanny. The house also heats up much faster now, I have almost instantaneous hot water and my energy bills are noticeably lower.

The guy who fitted it for us told me that these boilers really are the best out there.

I would recommend this product every time…

  • Name : Simon

Date : 10 June 2013

Item purchased :  W.B Greenstar 24i Junior Combi

Rating : 3 /5

Comment :

Had a Worcester Greenstar junior 24i boiler installed and it ran ok for a while. Just after the 2 year guarantee ended it leaked all over my new kitchen. A local heating engineer discovered there was a spring clip missing from the boiler. Worcester offered parts only leaving me to pay for the labour costs of fixing the faulty boiler. I won’t be buying another of their products.

  • Name : McCarthy

Date : 03 January 2015

Rating : 1 /5

Item bought : W.B Greenstar 28i Junior Combi

Comment :

The temperature fluctuates so much…between arctic cold (for days) and suddenly scorching hot. These problems started as soon as the boiler was fitted.

time taken off to wait for someone to fix it (they’ve never been there for any appointment ever) only for them to turn up the next day…

A danger if you have little children or elderly as unexpected boiling water.


  • Name : Guest review

Date : 26 March 2013

Item bought : WB Greenstar 28i Junior Combi

Rating : 2 / 5

Comment :

We used to have a reliable back boiler which worked fine, never had a problem. On the recommendation of an engineer we got a Worcester boiler fitted. Since it was installed we have had problems with the loss of pressure, parts had to be replaced, but by far the worse problem is the noise it makes when heating up the water, this can best be likened to a jet aircraft doing engine run tests. To say it was loud would be an understatement. 12 times in 3 years we have called out the engineer they came, they saw they tweaked something and assured us it will be Ok now’. Fat chance. We wish we had kept the back boiler!


  1. Why choose a Worcester Bosch Accredited Installer?


  1. Up to a 12 year guarantee on all Greenstar Lifestyle boilers fitted with a Greenstar System Filter 
  2. Friendly help and advice for your specific needs 
  3. New installations, servicing and repair work
  4.  Peace of mind with Gas Safe and OFTEC registration

     2.  Can I use artificially softened water in the heating circuit with my boiler?


You can have a water softener in combination with our boiler as it will prevent the hot water circuit from scaling up and losing efficiency.  However, the central heating circuit should be filled with hard water and a chemical inhibitor.

3.  We’ve had a power cut. Does that affect Easy Control?

Ans. The EasyControl does not have  power and hence, the heating appliance gets switched off. The EasyControl remembers last/previous set settings. As soon as the power returns, the thermostat reboots, the current time is retrieved from the internet server and the appliance restarts according to the clock program.

4. How long is the guarantee on an FastTrack installation?


This depends on the product package you have:

Greenstar CDi Compact comes with a 10 year guarantee.

5 . The thermostat updates automatically. Can I turn this off?

No, automatic updates cannot be switched off. The thermostat automatically checks for the updates on the server, which is installed automatically. The thermostat stays up-to-date so you can benefit from any product improvements.

6. My boiler is producing a ‘gurgling’ sound. What could be the cause?

This gurgling sound may be caused by a blocked condensate pipe, please contact your installer to resolve the issue.


  • Maintenance

It’s likely that most of you may not pay attention to the boilers during spring/summer, right ! But even during downtime, maintenance is very much crucial and it helps avoid bigger system breakdowns during the time of actual usage

  • Recycling of water

Boilers utilize a closed system. This means that they recycle heated water repeatedly and don’t use any more energy than the majority of the other available heating systems.

More often, they are actually the most environmentally friendly decision especially if you select a high-efficiency boiler installation. This will keep your energy bills low and help you save money on your water heater.

  • Boilers Don’t Always Boil Water

In a boiler system, the heat exchanger is apparently a tube over the burner flames, through which the water flows.

As the water flows over the flames, it is heated to the proper and appropriate temperature before moving on to heat the house. Because of the way the heat exchanger is constructed, the water is not meant to stay over the flame long enough to boil, hence it does not always bring the water to boil.

  • How Often Should I Get My Boiler Serviced?

Getting your boiler serviced when there doesn’t appear to be any issue may seem unnecessary, but servicing your boiler once a year should help to prolong its lifespan.

Having an annual service should help you avoid unforeseen problems with your boiler, and keep it running efficiently.

  • The first boiler ever made was with a safety valve which was designed by Denis Papin of France in 1679; boilers were made and manufactured in England by the end of the 18th century. Early boilers were made of wrought iron which was much less effective; as the advantages of high pressure and temperature were realized, manufacturers turned to steel.
  • Boilers utilize a closed system. This means that they recycle heated water repeatedly and don’t use any more energy than the majority of the other available heating systems.


The boilers in the market seem to satisfy different and substantial requirements in various ways. The utility and sustainability thus seem to be the conclusive key factors that sum up the wholesomeness of an appropriate boiler. After a deep and extensive amount of research, we have refined out the essentials one seeks when in search of a device for heating water for homes. One seeks out the best in product with best of reliability and best assured quality. After a deep and extensive amount of research, we have refined out the essentials one seeks when in search of a device for heating water for homes. The boilers in the market seem to satisfy different and substantial requirements in various ways. The utility and sustainability thus seem to be the conclusive key factors that sum up the wholesomeness of an appropriate boiler. No user wishes to spend extensively on the installation, the maintenance and the repairs of the once installed boiler.  Nor does any user wish to exhaust the available resources and risk the safety of the members under the hazards of an ill manufactured boiler. One seeks out the best in product with best of reliability and best assured quality. Most of all we seek one that keeps the money spent at maximum utilization and thus, we can conclusively say that Worcester Bosch offers such assurance and reliability.

With much said, we have conclusively arrived at the opinion that Worcester Bosch and its boilers portray an incredible performance. Yet, the Model, Greenstar I Junior Combi model does not seem to establish the foreseen expectations of the brand. Much to suffice and supplement the needs of a customer, the brand has replaced these variants today with much more innovative substitutes.

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