Customer Testimonials

Below is a handful of comments from Sentinel customers. More in-depth details of customer experiences are available in our Case Studies section.

See our full list of domestic case studies See our full list of commercial case studies


  • Chris Jones of Rothwell Plumbing Services Limited, North East says: "Many of us were brought up through the heating and plumbing sector relying on Sentinel products."
  • Colin, a Self Builder from Lincolnshire, says: "Very rarely have I had such fantastic customer service from anywhere in the industry. I am now a big fan of your company and I will certainly put Sentinel on my list of preferred suppliers. I will certainly be recommending Sentinel products to other self builders and tradespeople that I know."
  • Tim Dandy of TD Plumbing and Heating, Hampshire says: "Fitting the Eliminator is a breeze! I'm very happy with it." 
  • Brian King, 'CombiKing', Grimsby and Cleethorpes says: Sentinel X100, X400 and X800 are part of our staple diet. We know it does the job and we know from our records that jobs where Sentinel has been used are jobs that go well."
  • Dale Clarke of David Clarke & Son Plumbing & Heating, Hinckley says: 'I don’t think we would seriously consider using anything but Sentinel in the jobs we do – we have built our reputation with customers on quality and to achieve quality you use quality at every level and water treatment is no different.'
  • Derek Cosh of C&S Construction, Oxford says: "I bought an Eliminator for my own home - having earlier purchased a competitor unit that I was warned by bad reports might not be up to the job. I fitted it myself very easily - the other unit would have required a plumber to do it - and it's already working well. It's easy to clean and drain which was essential to me. I can't find fault for its ease of installation or use."
  • George Nelson of George Nelson Plumbing & Heating, Belfast says: "When you use a good quality product for many years and it doesn’t let you down, you stick with it. All the boiler manufacturers I respect say use a good quality water treatment product and mention Sentinel by name."
  • Jeff Marsh of J E Marsh, Norfolk says: "The Eliminator was very easy to fit and it's working well. The system it was installed on was quite dirty and it's already working well in conjunction with X400 cleaner. In a month's time we'll flush the system and add X900.

See our full list of domestic case studies


  • Dave Ewins of Davanna Heating Ltd, Truro says: "It was really eye opening and encouraging to see a supplier showing so much interest in training installers. Sentinel has been really helpful and I will certainly be using their products whenever we install Ground Source Heat Pumps in the future."
  • Mark Howard from British Gas Business says of KalGUARD: "We have been highly delighted with this scale prevention product. Since installation 3 years ago, the KalGUARD has performed very well and is virtually maintenance free."
  • John Bailey, Commercial Systems Director at Vaillant says: "Because our systems are designed to the highest standards of efficiency and performance, there can be no compromises with the fluids that are circulating within them, otherwise optimum levels of efficiency and performance cannot be maintained. This is why we chose to work with Sentinel Commercial. The research and development that goes into their product range is exceptional, and the fact that they offer technology-specific fluids is key."
  • Jim Christofides, Head of Maintenance at Blackpool Zoo says "After only a short time on site, the system was fully clean, which has restored its operation to a very high level of efficiency – all the components are back working superbly. This is great news for the zoo as we are now operating a cost-effective system and minimising our carbon footprint."

See our full list of commercial case studies