If your radiators run cold at the bottom or your heating feels sluggish, a power flush is often the fix. Here's how to tell if you need one and what it costs in Renfrewshire.
The signs you need one
Radiators cold at the bottom but warm at the top, rooms slow to heat, a noisy boiler, or dirty/black water when you bleed a radiator — these all point to sludge build-up in the system.
Sludge makes your boiler work harder, costs you more to run, and can shorten its life. A power flush clears it and rebalances the system.
What it costs
A power flush in Renfrewshire typically costs £350–£600, depending on the number of radiators and how much sludge has built up. Adding a magnetic filter afterwards helps keep the system clean.
It's often recommended (or required) alongside a new boiler, so the new unit isn't pumping old sludge around.
Frequently asked
How long does a power flush take?
Most power flushes take 4–8 hours depending on the number of radiators and how blocked the system is.
Is a power flush worth it?
If you have cold spots or a sluggish system, usually yes — it restores efficiency and protects the boiler, often paying for itself in lower running costs.