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Endorsed by

Which

?

Trusted Traders

Sleeman Heating Limited

Logo on white
Profile thumb heating expert logo

4.9

20 Reviews

About

Hi – I m John Sleeman.

My company installs energy efficient German and Dutch condensing boilers, and solar panels and we specialise in heating installations in North and Central London.

Aims

To offer competition to the large heating companies who seem to charge a high price for services that are adequate but unexceptional. I aim to provide a good quality service at a competitive price.

I offer good technical knowledge of central heating, plus the ability to design systems that conform to the best modern standards. Good communication with customers is important to me, as is the continued good operation of my installations. I offer a 2 year guarantee on my workmanship and the boilers I install are covered by guarantees on parts and labour , some of them for 5 years. I use only responsible and competent co workers.

Services provided

Boiler replacement

Complete Heating Installations

Unvented hot water systems

Solar powered hot water

What we do

  • Boiler, central heating and gas engineers

    • Boiler installation
    • Boiler repair
    • Radiators and central heating
    • Boiler servicing
  • Renewable energy

    • Solar water heating
  • Heating contractors

    • Central heating systems (installation and servicing)

Customer reviews

4.9
20 reviews
Customer Service
5.0
Quality
4.9
Value
4.9
Sort by
Replace the old boiler with a water tank for a Vaillant combi boiler
Customer Service
Quality
Value
It was nice and easy to work with John, very professional and tidy work, useful advice, all the quotations and estimations came to be right, very happy.
Customer in Greater London28/10/2019
Excellent all round
Customer Service
Quality
Value
John fitted a new boiler for us: we're extremely happy with the work and would highly recommend him. He was extremely easy to work with, gave us some excellent advice regarding the choice of boiler (we've ended up with a much better solution: the two other heating engineers we got quotes from simply suggested run of the mill systems; John took time to understand our needs and requirements, and proposed something that really suited us). The two-day job was performed efficiently, tidily and courteously, and John was very accommodating dealing with some unexpected issues with our gas supply. His quote was also very competitive and we're delighted to have found someone who we would have no hesitation going back to for future work.
Daniel08/07/2019
Highly recommended
Customer Service
Quality
Value
John fitted two central heating boilers and recommended a product that was perfect for our requirements. Reliable and thorough and highly recommended.
Customer in Greater London13/03/2019
Highly recommended
Customer Service
Quality
Value
John installed a new boiler for us. We are very pleased with his work, he is highly professional. He also undertook some unscheduled work for which we are grateful.
Breege, London13/06/2018
Excellent job
Customer Service
Quality
Value
Installed unvented hot water system, neat job, absolutely no problems. Inspires confidence.
Gudrun, London01/05/2018
Professional & competent
Customer Service
Quality
Value
Very thorough. Took longer than expected, but the explanation was acceptable.
Matthew, London14/06/2017
Reliable, professional
Customer Service
Quality
Value
Great job for renewal of entire heating system, no problems with new boiler and great savings from solar hot water system.
Oliver, London09/06/2017
Fixed a complicated issue.
Customer Service
Quality
Value
We had numerous people try to identify our plumbing issue, and John was the only one able to do so. He then came back to implement the solution and worked 2 x 12 hour days, and left the house tidy. Very impressed.
Ruth, London06/06/2017
Very happy - super fast work
Customer Service
Quality
Value
Extremely fast and efficient service. My existing boiler was on its last legs. Phoned John on Tuesday, he came to have a look on Wednesday, gave me a quote on Thursday and fitted the boiler on Monday! Less than a week from start to finish. Boiler was installed in one day by John and Marko, both are very friendly and professional and even cleaned up afterwards. Definitely recommend!
Philip, London08/05/2017
Expert, friendly heating engineer
Customer Service
Quality
Value
John Sleeman put twice a new boiler into my premises. He gave very good advice, took time to explain everything and was efficient with good time management. I have no hesitation to recommend him to further customers.
Angelika S16/09/2016
Trustworthy, efficient, reliable and eloquent.
Customer Service
Quality
Value
I had had some work done previously by another contractor (not a Which? trader) which proved to be faulty and was at great pains not to have a repeat of this so asked a trusted architect for a recommendation and he forwarded Sleeman Heating's details. I can attest that was a good call. I received excellent service. Fault found and corrected with a cost effective solution professionally, efficiently and punctually with an eloquent, pleasant and calm manner.
Suzanne H09/09/2016
Reliable, friendly and efficient
Customer Service
Quality
Value
Very glad I chose this trader. Arrived on time and did exactly what was needed. Will certainly use them again and would recommend them.
Emma, London27/02/2016
Trusted tradesman
Customer Service
Quality
Value
John has installed boilers at two of my properties. Both were difficult jobs. I have used John because I have confidence in his abilities and he has also found ways to avoid costly measures such as scaffolding. I will use him again for any other installs and servicing.
CMR40288848426/05/2015
First class job.
Customer Service
Quality
Value
We were very pleased with our new boiler installation. His timekeeping was excellent, he was organised, professional in his work, and all appears well. He was very tidy and pleasant, and we had full confidence in him.
David, London26/05/2015
Outstanding professional job
Customer Service
Quality
Value
Mr Sleeman recommended and fitted our boiler 2 years ago and I couldn't be more pleased with both the initial installation and price and in the follow up servicing. All thoroughly professional and efficient. I can't recommend him highly enough.
Andrew, London08/04/2015
Nothing fazed him on a difficult job
Customer Service
Quality
Value
John Sleeman is an excellent heating engineer and a very considerate man, He did a great job which took much longer than anticipated but didn't over charge for the extra time. Will use him again.
Ian, London02/03/2015
Great job
Customer Service
Quality
Value
Very professional, good communication, helpful and punctual.
Mark, London12/12/2014
The best trader I've ever appointed
Customer Service
Quality
Value
John replaced our old boiler in April 2010. Amongst 5 quotes we obtained, the one from John was not the cheapest. But we appointed him for what he said made the most sense to us and we felt that he's honest and most importantly experienced. We were not wrong. For a Victorian house, this kind of work will always encounter something unexpected. John kept us informed about the problems and provide solutions. Now 4 years later, both my wife and I agree that with all the traders who worked on our house, appointing John has been the best decision we made. John is friendly, punctual and has meticulous attention to details. He is still servicing our central heating system every year since then and we feel safe and warm with his phone number on our contact list. For heating solutions, I recommend John Sleeman unreservedly.
KaneZhang18/10/2014
Excellent service.
Customer Service
Quality
Value
Sleeman Heating offers an intelligent and conscientious approach to heating solutions - and very good value. They run an admirable apprentice scheme too.
Rachel, London26/09/2014
Very high standard of work.
Customer Service
Quality
Value
Sleeman Heating installed a new central heating system. It was a first class service from start to finish. I was given excellent advice on how to go about the job, kept informed of costs at every stage. Everything was completed to a very high standard on time and to agreed budget. Couldn't recommend highly enough.
Josephine, London21/09/2014