Sentinel Internal Leak Sealer 1Ltr

Product Code: 99730
Sentinel Internal Leak Sealer 1Ltr
Product Code: 99730
Internal Leak Sealer for small inaccessible leaks and weeping joints in all types of indirect heating systems including those containing aluminium components. Compatible with elastomers.


  • 1 Year Manufacturer's Guarantee
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Safety Data Sheet
€17.45 Incl. 20% VAT
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Additional Information
Technical Specification
  • Brand : Sentinel
  • Sealant Adhesive Volume : 1 Ltr
  • Product Type : Internal Leak Sealer
  • Pack Size : 1
  • Manufacturer Guarantee : 1 Year Manufacturer's Guarantee
  • Pieces in Pack/Case : 1
Product Contents
Delivery & Returns


Standard delivery: €15

Free delivery on all orders over €70.00

Click here to see information on our delivery charges and times



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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Sentinel Internal Leak Sealer 1Ltr is rated 4.75 out of 5 by 32.
Rated 5 out of 5 by from Sentinel Leak Sealer I have used this product for over 12 years. The condition of Systems is always clean and corrosion free. The price at Screwfix is excellent.
Date published: 2016-09-24
Rated 5 out of 5 by from Great Very good product I really recommend it, work on the first time really great good nice brilliant smells nice !!!!!!!!!!!
Date published: 2016-04-18
Rated 5 out of 5 by from Sealed the leak Using this marked the end of a 2 month search for a leak that couldn't be found. The noise coming from the central heating pump has changed noticeably since adding this but I cannot comment on whether this is a good or bad thing... something to keep monitoring I think.
Date published: 2016-04-05
Rated 5 out of 5 by from Brilliant Had a mystery leak somewhere under floor that could not be detected, leading to regular pressure drops and topping up of system on a daily basis. I thought I'd give this product a try before ripping the entire flooring up and hey presto it worked! I poured it into the system through the top of the bathroom towel rail as this was easy access, turned on the boiler for a short while as per the instructions and that was it. Several months later still no problems and pressure is constant. One of the best products I've used, highly recommended.
Date published: 2016-02-29
Rated 5 out of 5 by from Easy to use and works! Had a small leak somewhere inaccessable, so drained the system a bit, poured into top of bathroom towel rail (highest point), refilled and bingo. No leak.
Date published: 2016-01-23
Rated 5 out of 5 by from Finally. Job done. After a very long time suffering the inconvenience of the boiler not coming on in the morning because of the loss of pressure overnight we are finally waking up to a warm house. Adding the sealant could not have been easier. I used a towel radiator upstairs as this is the highest point and filling through the top vent is straightforward. Vent any remaining pressure from the system, drain off a litre(ish), remove the vent plug from the radiator, empty contents into system, refit plug, pressurise system and let the sealant do the work. Hey presto! No loss of pressure to date. For this price and the short time to do the job it can only be 5 star and it only needs 2 words. It works.
Date published: 2016-01-21
Rated 5 out of 5 by from Simple and affective sealer Since moving in a year ago have had to replace most radiators as they had pin holed over several months during this time and kept loosing pressure and having to top up system. I had assumed this was due to radiator leaks but problem continued. As the pipe run is plastic pipe set in floor with copper tails to radiators it is impossible to locate actual leaks. I have assumed the compression joints in floor have been disturbed when fitting new radiators which are metric size to replace imperial ones. Having purchased product I drained required amount of water from system using air vent plug on bedroom radiator and filled system through bathroom ladder radiator, which has vertical bleed vent in top. This made it a simple way to pour fluid into system with jug. I found it required the bathroom radiator to be fully opened to distribute around total system. Result a system which is not leaking and has not required topping up. (Only after 1 week hence only 3 * for reliability.) So far so good!
Date published: 2015-12-31
Rated 5 out of 5 by from Extremely impressed I had a minor leak on my 9yr old Baxi combi boiler, that was a steady and continued rate of drip. My gas service engineer advised what would be involved in the repair, but agreed that this stuff would be worth a try to save money. I fed this into the system via my bathroom towel radiator, using a funnel, then set the heating to run. Within 15 minutes the leak was sealed. It's fair to say that I'm more than happy with the result. It certainly buys me some time before I may have to repair or replace the boiler.
Date published: 2015-11-15
  • 2016-10-27T07:57CST
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