Signs Your Central Heating Needs a Power Flush

What is a power flush?

A power flush pushes a high-flow mix of water and cleaning chemicals through your entire heating system - boiler, pipes, and radiators. It breaks up and removes the sludge, rust, and limescale that builds up over time. Once it is done, the system runs more efficiently and your radiators heat up evenly.

How do I know if I need one?

The main signs are:

• Radiators with cold spots (especially at the bottom)
• Radiators that take a long time to heat up
• A noisy boiler (banging, kettling, or gurgling sounds)
• Discoloured water when you bleed a radiator
• Higher energy bills than you would expect

If your radiators have cold spots at the top rather than the bottom, you probably just need to bleed them instead.

How much does it cost?

A power flush for a typical 3-bed house with 8-10 radiators costs between £350 and £600. It is a lot cheaper than replacing radiators or a boiler that has failed because of sludge damage.

How long does it take?

Usually 4-6 hours depending on the size of the system and how much sludge there is. One of our customers had a central heating problem that “was quickly diagnosed. The system was power flushed and now works better than ever.”

How often should it be done?

Every 5-6 years is a good rule of thumb, or whenever you notice the symptoms above. If you are having a new boiler installed, we will always recommend a power flush first to protect the new unit. A magnetic boiler filter can also help keep the system clean between flushes.