10 year guarantee

A

Specification

Central heating output
35kW
Solar compatible
Yes

Dimensions

Height
760mm
Depth
360mm
Width
440mm

Greenstar CDi Classic System highlights

  • Highest central heating output of the Greenstar system boiler range
  • Simple boiler control knobs with digital display and one button commissioning mode
  • Worcester's CDi Classic has set the heating industry benchmark for efficiency, helping to reduce energy usage
  • Low energy pump reduces electrical usage
  • Frost protection is included, reducing frost risk if installed in a garage or a loft
  • Can be used with Greenskies solar panels for energy and cost savings
  • Choice of controls enables greater comfort and economy*
  • Large Condensesure style siphon built into the boiler - eliminates frost risk*

Worcester Diamond Accredited

Worcester Bosch Accredited Installers (WAIs) are accredited to install Worcester Bosch boilers to the highest standards.

Worcester Bosch quote "We want to provide homeowners with peace of mind when they are upgrading their home heating system. We invite heating engineers who we deem as reputable, quality-conscious and representing value for money to join our Worcester Accredited Installer scheme.

The installers must have relevant Gas Safe approval to be a Worcester Accredited Installer.

We check the installers’ Gas Safe, accreditation on a regular basis."

What our clients are saying

W. Williams Boilers & Heating IconW. Williams Boilers & Heating

36 Hurst Road, Twyford, Reading

4.9 51 reviews

  • Avatar Ken Cheng ★★★★★ 3 weeks ago
    What a fantastic job. Peter and Darren were both extremely professional and courteous. The workmanship was faultless and they managed to minimise disruption to existing fixtures and decoration. All my questions re. my boiler and the Nest … More system. Would use them again without question and recommend without hesitation.
  • Avatar christopher nicolaou ★★★★★ a month ago
    ref: Invoice 748351
    From start to finish the whole process was faultless!
    Wesley was professional, polite, tidy and willing to answer any questions or worries I had.
    He provided an extensive inspection to ascertain my requirements, swiftly
    … More quoted accordingly, then promptly booked me in.
    The installation was just as professional too, and carried out as quoted.
    Would highly recommend him to anyone looking for a boiler installation.
  • Avatar Roman Abylkhatov ★★★★★ in the last week
    There was a bit of confusion at the start as I didn't receive any email with a quote I made online (I made it very quickly). But once I've agreed to the quote and received the papers I realized I wanted a different system. It … More was all sorted out well with a bit of delay due to the change. But the team worked very well with a little disruption at home and advised on how to operate the system. Very happy with the Nest start meter as I can now set different temperature for the day and night, and do it on the phone. Worth investing an extra £200.
  • Avatar Garth ★★★★★ a month ago
    Reference 748320 - new boiler installation
    Removal of the old and installation of the new completed in a single day. All professionally and neatly done. Was a pleasure to have Pete here for the day. Very happy with the result. We definitely
    … More recommend this company.
  • Avatar Trevor Knight ★★★★★ a month ago
    Wesley Williams responded promptly to my request for a quotation to replace my CH boiler. The Quotation was professional, comprehensive and identified optional extras. Wesley and his team ( Darren & Peter) arrived promptly on the agreed … More date and dealt with the removal of the old boiler and installation and testing of the new boiler in a very diligent manner. They identified a problem with the gas supply pressure to our house and promptly informed the local gas authority which immediately resolved the problem. Peter returned to finally check and commission the installation.
  • Avatar Nik Murthy ★★★★★ a month ago
    I was advised my boiler flue did not have sufficient airintake after a service. I contacted multiple plumbers most of whom advised to change the boiler flu at an elaborate cost. Wes was the most efficient, fair and reasonable in terms of … More quoting for the work but then found a better solution after inspecting the property and noticing the boiler would be hard to access to fix the new flue (something other plumbers did not care to mention). The other plumbers would have probably started the work, come across the same problem and by then I would be £££ down, safe to say I will be using Wes & his team again - they were all friendly, fair and efficient.
  • Avatar Graham Lawson ★★★★★ in the last week
    Very professional friendly service. Thouroughly recommended. Will definately use them again.
  • Avatar spit sthedog ★★★★★ a week ago
    Dealt with Wesley initially about a Boiler Overrun wiring issue that wasn't done properly by the previous installer. He spotted the problem straight away.
    His engineer Peter came the next day to fix the problem, and do some other
    … More work.
    Very impressed by the service.
    Would highly recommend this company.
  • Avatar Hideh Rowghani ★★★★★ in the last week
    I wish all traders were as professional. They arrived at the appointed time, carried out the job quicker than they had quoted. I have no hesitation to recommend them to all.
  • Avatar Henry Winstanley ★★★★★ in the last week
    Invoice ref: 748255
    Had a new boiler installed and the service from start to finish was excellent as was the quality of work. They arrived when they said they would and completed the installation when they said they would
    I could not have
    … More asked for more
  • Avatar Chris Cassidy ★★★★★ a month ago
    Wesley and his team spent 2 days installing a new boiler and removing an existing water tank & cylinder. Extremely impressed by his team's professionalism and hard work. Also followed up quickly after some teething problems with … More the new system. Highly recommended.
    Invoice: 748233
  • Avatar John Doughty ★★★★★ in the last week
    Wes and his team are real professionals. Our new boiler and pressure system was expertly installed and we are delighted with the improved performance of our system. The team are courteous, organised and reliable. Highly recommended. Thanks. … More
    Ref Invoice No 748243
  • A Google User ★★★★★ 2 months ago
    Wesley Williams and his team have just replaced our unreliable boiler with a new Worcester boiler. They worked quickly, quietly and were very clean. Setting the system up necessitated visiting all rooms containing radiators and also … More the loft space and everything was left in perfect order. All achieved at a very fair price. Heartily recommended.
  • Avatar Richard L ★★★★★ 2 months ago
    Wesley Williams and his team have just replaced our unreliable boiler with a new Worcester boiler. They worked quickly, quietly and were very clean. Setting the system up necessitated visiting all rooms containing radiators and also … More the loft space and everything was left in perfect order. All achieved at a very fair price. Heartily recommended.
  • Avatar Cath Jones ★★★★★ in the last week
    Wesley recently replaced our oil boiler. Great communication, a really quick turnaround and did a fantastic job, left everything spotless. (inv 748240)
  • Avatar Richard Puttock ★★★★★ 3 months ago
    W. Williams boilers were very professional. Their standard of work was first class with everything completed extremely neatly and quickly. They also installed a new heat exchanger for the swimming pool which is much more efficient than … More the old system. Wesley is very knowledgeable in all aspects of heating. First class company. Great to have engaged them.
  • Avatar Emma-Jean Wells ★★★★★ 5 months ago
    After getting quotes from a few places for a new boiler we really liked Wesley and his approach. I had lots of random questions prior to confirming with him that we would use his services that he took the time to answer and explain.
    They
    … More fitted us in for a new boiler the next week and we had Pete and Darren come and spend 2 days installing the boiler, new valves on our radiators and nest. These guys were so polite and friendly and super tidy!
    Even after I had paid the full amount Wesley still took the time to answer more random questions I had and we felt really valued as a customer.
    Would 100% recommend this company to anyone considering any boiler work.
    Invoice: 748223
  • Avatar Michael Davies ★★★★★ 3 weeks ago
    Wesley arrived promptly to carry out the annual service on the boiler, wearing the appropriate PPE and self distancing. He also fitted a new controller and cured the vibration on the cabinet. Delighted and will certainly ask him again. … More Thank you. Michael
  • Avatar Gerry Brittan ★★★★★ a month ago
    After initial difficulty in contacting W Williams, I think due to them being very busy, Wesley visited my home to discuss the proposed work. We agreed a plan which included a new boiler and I later received a very comprehensive estimate. … More I agreed the price and work was scheduled to start within ten days. Wesley and his brother arrived on time and began the work which involved replacing and lagging all the pipe work in the garage loft and repositioning other items next to the new boiler. Work was completed the next day and I was extremely pleased with the result. A very neat and tidy job. I would have no hesitation in recommending W Williams Boilers and Heating.
  • Avatar Neil Stewart ★★★★★ in the last week
    This company was recommended to me by a neighbour and I was very impressed - really good service, efficient and professional. Five stars from me :)
  • Avatar Kevin Harte ★★★★★ 2 weeks ago
    A very professional and courteous service, the quality of the work was excellent and a real can do attitude makes all the difference . I would highly recommend this company and compliment Wes and Darren for their very respectful approach … More . Invoice 748206
  • Avatar Tracy Lee ★★★★★ a month ago
    I recently had a warm air boiler replaced with a full central heating system, this was no easy task in my house. The engineers were brilliant, they were professional, friendly and nothing was too much trouble. I am very pleased with the … More end result and would have no hesitation in recommending this company.
  • Avatar Rob Hewison ★★★★★ a month ago
    Wesley Williams was one of three installers who quoted for our boiler and hot-water tank replacement. He was the most expensive of the three (though by only a small margin) but we chose him for his professional, knowledgable approach when … More he came to survey, his instant and detailed response whenever we asked questions about the quotation, and the fact that he could install the make of boiler we preferred, Worcester-Bosch.
    It was a good choice. His two engineers, Pete and Darren, were as pleasant, professional and competent as their boss. The job was completed in the two days quoted, the system works well, the installation is very neat, and they tidied up well at the end of each day.
    Who could ask for more?...
  • Avatar Penny Lowe ★★★★★ 2 months ago
    Superb service as usual from Wes - even in these extraordinary times. Replacement boiler fitted within a couple of days of getting called out. Highly recommended.