Heating System Flush: Why and How

Professional radiator repair


Central heating systems are largely easy to maintain and cheap to run. However, to keep them that way, some maintenance is necessary.

What is a heating system flush?

A heating system flush is the process of ‘flushing’ your central heating system in order to remove residue – called radiator sludge – from the pipes and radiators.

Why do a heating system flush?

Radiator sludge is caused by a build up of materials within the system, mostly due to corrosion.

This causes your heating system to work less efficiently, sometimes preventing your radiators from working at all. A heating system flush gives the system a thorough clean ­out, allowing it to function at its optimum capacity. A heating system flush:

  • Will help save you money on your heating bills, as your system will be working more efficiently
  • Will prolong the life of your system
  • Will help save energy overall
  • Allow more even heat distribution

How often should I do a heating system flush?

It is generally recommended to carry out a heating system flush every 5­6 years, to keep your heating system working as well as it should. However, many people choose to wait until a problem arises. The choice is yours, however the general consensus is that prevention is better than cure.

There are a few signs and symptoms that can be attributed to a build up of radiator sludge:

  • Central heating system taking a long time to heat up
  • One or more radiators cold at the bottom, or not working at all
  • Radiators need bleeding frequently
  • Boiler making strange noises

How do I carry out a heating system flush?

It is possible to remove each radiator individually to clean them. However this is laborious and time consuming, and is unlikely to offer the same effective clean as a power flush. Radiator sludge can also build up in the piping of the heating system, and this won’t be removed with this method.

A professional heating system flush – a power flush – is carried out with specialist equipment by central heating system engineers. The system is flushed through rapidly with water, taking the radiator sludge with it and leaving clean water behind. There is also a chemical added to the water that helps to prevent further build up of radiator sludge. The whole process can take a few hours.

Gas Services are able to carry out power flushing, along with any other gas central heating works, at fair and competitive rates. All of our engineers are highly qualified and RGI registered, for your safety and peace of mind. Call us today for a no obligation quote.