"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."
"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!"
"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."
"Lost pressure in system ,could not find leak under restricted accsess of house so decided to buy this product . Almost bought a cheaper alternative but rally wanted this problem sorted .after draining system and installing this product 24 hours later problem solved !"
"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"
"I have a small leak in a pipe joint of the central heating system at my holiday home. The house has tiled and concrete floors so each spring after the system has been drained down for winter I have to replenish the system with the leak sealer and everything is OK for another year. A lot cheaper than excavating the floor and re-tiling and works every time."
"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."