Alternatives to powerflushing

  • Add descaling chemicals to the system , Circulate for two weeks, drain and refill with clean water and inhibitor.
  • Flush with clean water and add a magnetic / manual filter on the return to the boiler.
  • Take all the radiators off and jetwash them through.
  • Fix the actual problem directly, not flush to bring the system back to 'good health' - slow pump, blocked secondary heat exchanger etc.
  • Add descaling chemicals to the system, and leave them in. Check you use the right chemicals though, or you will do damage


I use top class powerflushing equipment, manufactured by Kamco, universally recognised as one of the world leaders in powerflushing. I have been using Kamco equipment since 2003, and find there kit and chemicals to do an excellent job, with a good balance of cost to result.

A powerflush essentialy involves circulating chemicals through your system with a large pump, these chemicals dissolve the sludge and scale that has built up from hard water and corrosion over the years. This job is usualy done when you have your boiler changed.

Danger - read this 

Many unreputable companies will tell you that you need a powerflush when you dont! If your not having your boiler changed then get a second opinion before paying for a powerflush. Often even a powerflush wont fix the problem. One very large well known national company uses it as there standard 'get out'. Remember quotes are free, as is advice and tips.

What the job entails

First of all the job will take ALL day, it will involve the engineer sitting by the machine circulating the water backwards and forwards through the system. First all of it, then one radiator at a time, then all of it again, then rinsing it with clean water. Depending on how your system is configured it may also be neccessary to isolate certain sections, expansion tanks for example, to prevent overflow. If its possible then running the boiler while the flush is running also helps as heat speeds up the chemical reactions. Be patient, it takes a while!


Very old systems

Weak systems should not be Power flushed as small leaks or weak areas WILL show up

Combi Boilers

Poor hot water on a combi usualy means a blocked secondary heat exchanger. This is not usualy cause for a powerflush


Only certain chemicals can be used with aluminium..... check your engineer know his job or your boiler will be ruined

Weeping valves

You know that little weep you get on the radiator valves sometimes? you need to tell me about it, because the flush will turn that into a proper LEAK!


10mm piping should not be flushed as it has a tendency to block up as large particles from the main flow pipes break off and 10mm pipe just cant take it through


Good chemicals are always worth the extra money. Fernox DS40 is an especialy good one as its not harmful to the enviroment


Manufacturers DO NOT insist on a powerflush, but they do insist on a decent flush.