Sentinel 88008 x200 Descaler 1 Litre, Clear

Used to help reduce the knocking noise in central heating pipework. Applied to central heating system as described in the instructions. There seemed to be an almost immediate effect on the noise reduction. Two weeks or so after, although not silent, it has reduced the knocking noise dramatically.

Product works very well and stopped our boiler from knocking.

Fair price, good product

I have a British gas service agreement that I have had for the last 20 years. For the last 3 years I have experienced the kettle'ing noise associated with the hard water in this area ( I have only known about this recently through my research). Every engineer has stated the only way to eradicate the noise was to replace my 15 year old balanced flu condensing boiler for round about £5000. After inserting this SENTINEL into my system I know have again an almost silent boiler. I must now consider wether to carry on paying the near £300 maintenance a year for an engineer to come and titivate my boiler with a paint brush to deposit any dust or residue into my kitchen.

I have used this for several years as my boiler is ancient and suffers from kettling noise.What happens is that the product cuts the noise significantly for maybe a year but then loses its effectivenessand needs to be replaced ; still its cheaper than a new boiler!

My boiler has been kettling for a while and I added a litre of Sentinel x200, after a few days it started making a noise that I imagine a brick in a washing machine might sound like.I was so worried about it that I called out a heating engineer, he said that my Valliant ecotec boiler was quite old (2009)and the heat exchanger was probably scaled up, but suggested that I put another litre of x200 in before thinking about more drastic action.I had already drained the system and cleaned out the magnetic filter prior to the first dose as well as giving the pump a good clean (the impeller was blocked solid,!) after adding x200 again the boiler continued to make horrendous noises but several weeks later it suddenly went quiet and seems to be working OK.Fingers crossed it will be OK, so put it in (x200) leave it in and be patient.

Did the job it was manufactured to do. Can't say owt more than that!

Did the job it was intended for by reducing banging noise from boiler. Noticeably reduced within half an hour of being circulated round system. Recommended