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Sentinel X400 System Restorer 1Ltr (89458)

1Ltr. Apply to existing systems for the removal of sludge and deposits. Iron oxide is broken down and dispersed through flushing.

  • Removes Sludge
  • Breaks Down Iron Oxide

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£16.99INC VAT (£16.99/Ltr)

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Rated 4.7 out of 5 by 25 reviewers.
  • 2016-05-03 T07:09:06.285-05:00
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Rated 5 out of 5 by central heating cleaner Used this on system with micropore and 15mm pipes. Works well no more cold spots in any radiators. Easy to add, drained some water off to de-pressurise added contents to radiator via plug. Re-pressurised system and let it do its thing. 31 Jan 2016
Rated 5 out of 5 by Excellent for old systems I have an 8mm microbore system that was installed in 1979. Despite having been power flushed in the last 2 years, the system really isn't working that well. I know several rads don't even warm up. I know that there are blockages too. We live in a very hard water area. Having added X400 in to the system and left to run for 2 days, Radiatprs that haven't worked now do. The hot water system is hotter, in fact, all the rads in the house are much hotter. The X400 was added to an empty rad and left to run through the system. As per the instructions/advice all rads were left fully open and the system was heated up. After 48 hours the difference can be felt. 13 Jan 2016
Rated 5 out of 5 by Sentinel X 400 Had a few issues with the central heating I was recommended this product so followed the instructions all the rubbish that came out of the system was quite shocking finished the job and now all working great, 23 Nov 2015
Rated 5 out of 5 by Central Heating System Cleaner If you are restoring an older CH system, this is THE cleaner to use. It loosens sludge, rust and general dirt. Leave it for up to 2 weeks then flush with clean water and add inhibitor. 30 Sep 2015
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2 Questions  2 Answers

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Good afternoon,

An additional radiator was added to my CH system, and the piping used for the additional radiator is plastic.

Is this product compatible with my system?

Kind regards

21 Mar 2016
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Hi there Ali,
Yes, it is perfectly safe to use Sentinel X400 High Performance Cleaner on systems with standard plastic plumbing pipework.
Kind regards,
Sentinel Customer Services
22 Mar 2016
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When and how would you use Sentinel X400 in your central heat
16 Aug 2015
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, Electrician
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Hi there
If you are tackling circulation problems, identifiable as cold spots in radiators, most often caused by sludge build-up. The formation of this sludge is almost impossible to completely prevent and it often settles in low flow areas of the system.

X400 High Performance Cleaner is the best central heating cleaner for this job as it breaks up, lifts and suspends this sludge, then allowing it to be flushed out of the system. In order to do this, it should be circulated, ideally at normal operating temperature, with all valves open and the pump set to maximum flow for a minimum period of 2 hours or until satisfactory performance is restored. In badly fouled systems, a period of circulation of up to 4 weeks is recommended

best regards
Sentinel Customer Services
17 Aug 2015
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Brand Sentinel
Model No X400
Pack Size 1
Pieces in Pack/Case 1
Product Type System Restorer
Sealant Adhesive Volume 1 Ltr
Total Product Weight 1102 kg
Volume 1 Ltr


Safety Data Sheet (COSHH)