Sentinel X200 Boiler Descaler 1Ltr Product Code: 43140

1Ltr. A unique, life-long system treatment for the elimination of limescale and boiler noise. Reduces fuel usage. Safe to use in all types of indirect central heating systems. Non-acidic.


  • Restores Boiler Efficiency
  • Eliminates Kettling
  • No Need to Flush - Stays in System
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Safety Data Sheet
Additional Information
Technical Specification
  • Brand : Sentinel
  • Product Type : Boiler Descaler
  • Volume : 1 Ltr
  • Model No : X200
  • Pack Size : 1
  • Manufacturer Guarantee : 1 Year Guarantee
  • Pieces in Pack/Case : 1
Product Contents
Delivery & Returns


Standard delivery: €15

Free delivery on all orders over €70.00

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€25.45 Incl. 20% VAT

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Sentinel X200 Boiler Descaler 1Ltr is rated 4.6 out of 5 by 36.
Rated 5 out of 5 by from Does what it says on the tin Bought this to address a 6 years old boiler that suddenly became noisy. It worked like a dream to the point where I swear the boiler is quieter now than when it was first installed.
Date published: 2019-02-07
Rated 5 out of 5 by from An excellent product Sentinel X200 a great product which does exactly what it says on the tin. You want to quieten your system then this is the product to use. Very easy to put into your system and effective almost immediately. The only downside is that the price needs to be looked at on all Bentinel products as they certainly are much cheaper elsewhere.
Date published: 2019-01-24
Rated 5 out of 5 by from It actually works! My 14 year old Vaillant combo was sounding like a kettle on steroids when it heating the water. I bought this stuff as the alternative is to put up with it or get a new boiler. I bought a little radiator filler kit too (basically a piece of garden hose and a couple of plastic attachments) and I isolated and part-drained a radiator and the added this stuff and re-pressurised the system. I’m no expert at all but that was easy enough. Well, what can I say? after a day or two the noise was significantly better! To be honest I am surprised it has worked as well as it has as it’s only 1 litre of stuff in my whole system and I would expect that there are more significant problems going on with such an old system. But work it does, and it saves me such an incredible amount of money for a new one or having to put up with a lot of noise!
Date published: 2018-12-26
Rated 2 out of 5 by from Boiler Noise I purchased this to hopefully quieten my boiler but it has been running for 5 days with no noticeable improvement. Instructions say it can take weeks to achieve its desired effect so fingers crossed. I will update if improvement occurs.
Date published: 2018-12-04
Rated 5 out of 5 by from Certainly is very effective Chemist in me insists this treatment can't truly *remove* scale, specifically because it has no acid, and only known way to mankind to dissolve calcium deposit is some acid. However I can attest X200 is certainly super-effective in treating boiler kettling. I've put mine into old&cheap boiler which developed odd gurgling and hissing - and in several hours it went dead quiet. Call me impressed. From what I see its quite foamy liquid - so I suspect it treats noise not by scale removal (no acid after all), but by "lubricating" heat exchanger and providing better heat distribution so no hot spots develop and liquid movement noise lot less audible. Also almost certainly likely it will prevent further calcium deposits by preventing them sticking. Reading their tech documents confirm my suspicion - you can easily notice Sentilel are careful word to avoid terms "de-scaler" and instead all packaging says "noise reducer" and they never state it "removes" scale instead saying it "cures the problem". So I'd say X200 is not effective treatment to unblock pipes already clogged with limescale, but certainly works super-well as preventative treatment and when noise is the main issue. If you need scale remover, you will have to use more aggressive product - like "Sentinel Deposit Remover", but it has to be used much more carefully and with through flushing after to avoid damage. Screwfix can improve on pricing for Sentinel products though - they way to overpriced there, much cheaper to pick elsewhere.
Date published: 2018-11-10
Rated 5 out of 5 by from Works well without bother Easy to use, does exactly what it says without any problems, the boiler noise was eliminated within a couple of hours
Date published: 2018-11-01
Rated 5 out of 5 by from Excellent product my boiler started knocking and making weird noises , it did the same a couple of years ago so i knew exactly what i had to do. One bottle of Sentinel 200 put directly in feeder tank and after a couple of hours its sweet as a nut. Highly recommend it and worth every penny.
Date published: 2018-10-02
Rated 5 out of 5 by from Used before - will use again Have bought this product before. Used it for my Baxi Back-Boiler Gravity-fed System that was suffering from 'loud kettling' After adding & running heating for a few hours - certainly noticed the difference - kettling reduced to almost none . Very pleased
Date published: 2018-09-11
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