How Much Does It Cost to Power Flush Central Heating?
£300 – £650
per system
A central heating power flush costs between £300 and £650 for a typical UK home, with the price varying based on the number of radiators, severity of sludge build-up, and whether chemical treatment is needed. Power flushing uses a high-flow pump to clear iron oxide sludge that causes cold spots and reduces boiler efficiency.
Average cost
£300 – £650
per system
Prices vary by region, property type and tradesperson. Always get at least two quotes.
What affects the price?
Number of radiators - most engineers quote per radiator at £50-£70 each, plus a base connection fee
Severity of contamination - heavily sludged systems require longer flushing times and more chemical cleaner
System size and complexity - homes with underfloor heating zones take longer to flush than a simple radiator system
Inhibitor and filter - adding a magnetic filter and system inhibitor after the flush adds £100-£200 but is strongly recommended
Labour vs materials
A power flush on a typical 8-10 radiator home takes four to six hours. Labour accounts for roughly 60-70% of the total cost; chemicals and the magnetic filter make up the rest.
Repair or replace?
If radiators have pinhole leaks caused by corrosion, a power flush alone will not fix them - the affected radiators will need replacing. A power flush before installing a new boiler is highly recommended to protect the new heat exchanger.
Questions to ask your tradesperson
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