A power flush is a deep clean of your central heating system — removing iron oxide sludge, limescale, and debris that accumulates over years of operation. It's not always required, but when it is, it makes a dramatic difference.
How a power flush works
A specialist machine connects to your central heating system and circulates a chemical cleaning solution at high velocity through all radiators, pipework, and the boiler. The machine captures debris in a filter, and the process is repeated until the water runs clear. The system is then refilled with fresh water and dosed with inhibitor.
Signs you need a power flush
- Radiators cold at the bottom but hot at the top (sludge settling)
- Black or very dirty water when radiators are bled
- Boiler making kettling or rumbling noises
- System slow to heat up or some rooms never getting warm
- Boiler firing but radiators barely warm
Do I need one with a new boiler?
If your existing system shows signs of contamination, most manufacturers recommend or require a power flush before installing a new boiler. Connecting a new heat exchanger to a contaminated system can void the warranty and shorten the boiler's life significantly.
What it costs and how long it takes
Power flush: £250–£400 depending on system size. Takes half a day to a full day. We carry out power flushes across Corby and Northamptonshire. Get a quote.