Sentinel X800 Ultimate Cleaner 1Ltr Product Code: 84921

1Ltr. A powerful cleaning agent for central heating systems. Specially developed for use with power flushing equipment. Removes iron and calcium-based deposits to restore circulation and system efficiency. Effective hot or cold. No neutralisation procedure is needed.
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Safety Data Sheet
Additional Information
Technical Specification
  • Brand : Sentinel
  • Sealant Adhesive Volume : 1 Ltr
  • Product Type : Ultimate Cleaner
  • Volume : 1 Ltr
  • Model No : X800
  • Pack Size : 1
  • Manufacturer Guarantee : 1 Year Guarantee
  • Pieces in Pack/Case : 1
Product Contents
Delivery & Returns


Standard delivery service up to 3 working days: €8.95

Free delivery on all orders over €70.00

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Hopefully you won't need to return an item, however, if you do, it is our aim to make this as simple as possible. By following the guidance below you can help us to help you when a product is not what you expected, or is faulty. Your statutory rights are not affected by this guidance.


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€23.95 Incl. 23% VAT

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Sentinel X800 Ultimate Cleaner 1Ltr is rated 4.9 out of 5 by 53.
Rated 5 out of 5 by from X800 Great product, did exactly as it described and unblocked pipe.
Date published: 2017-08-20
Rated 5 out of 5 by from Brilliant Faultless products which did exactly as it said on the bottle 5 Star
Date published: 2017-08-10
Rated 5 out of 5 by from QUICK AND EFFICIENT Had Scottish Power out to sort some problems with the combi and the engineer Nikki recommended to get the system flushed with a cleaner .I check out the Screwfix website (As you do) and picked up this at the local branch and put it in the system and having just drained it out it certainly has cleared plenty of sludge and debris and the boiler does seem to be working more efficiently ,will flush it through a couple of times and treat it to some inhibitor.
Date published: 2017-07-03
Rated 5 out of 5 by from Almost like magic I had a poor performing central heating system, cold rads, boiler not firing correctly, heat around the house was not good and boiler failed to fire correctly. I read the many reviews about what to use and went for Sentinel X800 for 3 reasons, good reviews on Screwfix and the fact that it was fast acting and most importantly would work with the cold water in the system as the boiler was not firing. fully removed 1 rad and cleaned it with a hose pipe then refitted and before refilling I put the system cleaner in via the Flomasta Universal Filling Kit (8145K) which I also purchased. The filled the rad with water. The pump soon pushed the solution around the system which seemed to clear some blockages as the boiler then fired. Left it running of r 2 solid hours and rads were getting hotter than normal, rads that usually struggled to get warm were getting very hot. I left the solution in for 4 days to fully ensure the system was cleaned and then drained. Colour of water was blacker than black, but I have a heating system that is not working well and I no longer have cold rads or rads not heating up. All in all about a full day to do all the work, but it was worth it and this product made it significantly easier.
Date published: 2017-04-20
Rated 5 out of 5 by from Good stuff, will buy everytime My central heating was fixed using this stuff, working 100% with it. I was a bit scared of it so only kept it in for 24 hrs. Drained it from the system . replaced it with Sentinal inhibitor and my heating was back to its poor self. Put some more of the cleaner in and it is 100% working again. It has been running for 2 weeks now. I am getting scared again. I am keen to drain it. I am thinking about it, but tthe system is running so well? a delema!
Date published: 2017-02-17
Rated 5 out of 5 by from X800 Central Heating Cleaner Having used this product in the past and needing to unblock a couple of radiators that wasn't working fully I decided to put some of the X800 cleaner into the system to help clear out the blockages. Its only been in a couple of days but the flow thought the radiators is much better and I'll leave it in the system for a bit longer before I flush and refill it back up.
Date published: 2017-02-02
Rated 4 out of 5 by from Very happy Struggling with yet another heating system sludged up and thought Id give this ago.. Was not disappointed. Added to the system and with 8 hours it was a completely different system. Don't forget after using this to protect your system with inhibitor X100 works well!
Date published: 2017-01-27
Rated 5 out of 5 by from Ultimate cleaner Read reviews on all cleaners & decided to try the X800 and i am not disappointed, Could feel a difference within a couple of hours.
Date published: 2017-01-16
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