Cost Guide
Power Flushing Cost Guide (2026)
Cold spots on your radiators, a noisy boiler, rising bills — sludge in the system is one of the most common causes, and a power flush is the fix. Here’s what it should cost and what affects the price.
Typical power flushing prices
For a typical UK home in 2026:
- A standard 3-bed home (up to ~8 radiators): typically £400–£600 including chemicals and inhibitor.
- Larger systems: expect the market range of roughly £400–£900 depending on radiator count and sludge severity.
- With a new boiler installation: we normally include a flush — protecting the new unit and its warranty.
What affects the price
- Number of radiators and system size
- How badly sludged the system is (severe magnetite takes longer)
- Access and pipework layout
- Whether a magnetic filter is fitted afterwards (recommended — keeps the system clean)
When a power flush is NOT the answer
A decent engineer will tell you when flushing won’t help: badly corroded radiators that need replacing, a failing pump, or a boiler on its last legs. We assess the system first and only recommend a flush when it will fix the problem.
Frequently Asked Questions
Want a fixed written quote?
We survey first, and the price we agree is the price you pay.