Fernox F2 Express Boiler Silencer, New Larger 400ml Can

I've introduced this into my central heating system three times over the past three years. On each occasion it has been successful in greatly reducing the knocking noise ('kettling') caused by the limescale build up on my old oil boiler. Whilst it doesn't change the fact that the boiler is old it does make it sound much better. I used the little adapter to introduce the product into a radiator bleed valve hole. Just as a point of note. If your radiator has an additional bleed hole in the radiator plug to let air out you can in fact successfully block this off with your finger whilst introducing the product. This might only work if you have an open vented system like mine. The last couple of times I was wary of this and removed the whole plug and used the bigger connector (no big deal). However on the third occasion I was running short of time to blocked off the hole with my finger when introducing the product. No guarantees though!.

I've used Fenox products in the past with good results. My heating system was dropping pressure so a can of their F4 sealant solved that. We have since had the system drained a few times for a new kitchen and bathroom and we got some new noises back in the pipes. Proper poltergeist/screaming banshee stuff!Straight back to Fenox for their F2 product. Ordered sat night arrived sunday around 11, pipes silent by 11:15.Inject the can into the system and open up all your radiators so the the product can circulate through.We have 9 rads over 3 floors.Cracking product from Fenox, does what it says on the tin.

Amazingly, my boiler was noisier than ever after using this. Not impressed!