Radiator Flush FAQs


Gas central heating is the most cost-effective and low maintenance heating system, provided that you do take the time to maintain it. If you have found that your radiators are not working as well as they used to, it may be that corrosion has occurred within your central heating system. This is common, and easily fixed by arranging a radiator flush.

Why might I need a radiator flush?

If your radiators are giving off less heat, have cold spots, or have ceased working altogether, a build up of sludge and scale within the radiators and pipes may be the cause.

Sludge within a central heating system is caused by rusting. The rust itself produces an iron oxide sludge within the radiators and pipes which can cause blocked valves and pipes and boiler problems. Sludge and scale within radiators can easily reduce heat output by 50%, wasting a great deal of energy and money.

A radiator flush will make your system run more efficiently, saving you money and reducing your CO2 emissions at the same time. A radiator flush will also prolong the life of your central heating system, and help prevent costly callouts and repairs that may be caused by corrosion within the system.

How do I know if I need a radiator flush?

Sludge build up is common and easy to diagnose. You may need a radiator flush if:

  • There are cold spots on your radiators, or some of them are cold all over
  • Radiators are cold at the bottom and only hot at the top
  • Your boiler breaks down due to a blocked pump
  • You find dirty water when bleeding your radiators
  • Your boiler starts making unusual noises (this should always be investigated)

How does a radiator flush work?

A radiator flush is essentially a deep clean of your central heating system. It is carried out by draining the system first, then refilling the radiators with water and strong chemicals. This solution is “powered” through the central heating system in a way that doesn’t cause any physical damage, breaking down the rust and sludge, and removing it as it moves through the radiators and the pipes.

After all of the offending substances within the system have been removed and your radiators are clean, a corrosion inhibitor is added to the water to help prevent any more problems occurring later on.

A radiator flush can breathe life back into a system that may have appeared to be giving up the ghost, often without the need to replace radiators or pipework. Gas Services LTD can carry out a radiator flush with as little disruption as possible and at a very competitive price, saving you money on your energy bills and giving you a warm house once again.