"I've used this leak sealer twice. Both times it was to solve the problem of pin sized holes in radiators caused by internal corrosion. The leak on the first radiator was cured within a few minutes of adding the leak sealer. The larger and more troublesome leak that I tackled recently took longer (about 24 hours) to seal but has been dry ever since. Compared to the cost and hassle of fitting replacement radiators, this product is great value and I have no hesitation in giving it a 5 star rating. If it doesn't work for you, then either you are being too ambitious or you haven't followed the (very simple) instructions."
"Used this after numerous attempts to stop weeping from two very hard to reach radiator valves. Simply drained a bit of water out of the system and added it to a radiator after removing one of the plugs The leaks have stopped and the system has not lost any pressure since I added the product three weeks ago. Very impressed (and relieved) I also bought the dosing kit, seems a bit dear for a few plastic fittings and a bit of tube, but it saved a lot of time and mess when adding the leak sealer to the radiator and I would recommend it."
"I never changed my rad valves after installing my condensing boiler, inturn they all started dripping and so I was forever topping up the system. Before replacing the rad valves I decided to give the senital leak sealer a chance and now 24 hrs later I am pleased to say the valves have stopped dripping. Full marks to this product then and I'll change the rad valves in the summer."
"Used to solve a leaking compression T which was in a difficult to get at location and would have required a drain down and new inhibiter. The leak was generating approx. 1 pint every 3-4 hours to give you an idea.
The liquid is very thick, I drained a few of pints from a rad in a tiled area and removed the whole bleed valve and used a 6inch cut of garden hose with a funnel to get it directly into the system. Took a good 5 mins to get it all in. Let the heating run on a boost and by 30mins the leak had virtually dried up and after 1 hour was good to go. Saved hours of work and wasn't looking forward to recharging the whole system, and bleeding it out. They didn't have the Fernox product in stock at my branch but am very pleased with the performance of this"
"Overhauled my central heating system this summer - flushed the radiators - fitted TRV's -changed a dodgy pump and then protected with Sentinel X100. A month later a chrome towel rail started to leak from a weld that must have rusted from the inside. I didn't want the hassle or expense of changing the radiator so thought I'd try SENTINEL LEAK SEALER first. I must admit I was doubtful it would work and initially it didn't but after about 4 or 5 days the leak stopped (sealed from the inside)! A month down the line and the repair has held - another great product from Sentinel at a great price from Screwfix."