Central heating power flushing

Over the years, heating systems collect black sludge (iron oxide) and limescale, especially in London’s hard water. It settles in radiators and pipes, blocks the boiler’s heat exchanger and makes the pump work harder. A power flush pushes a high-flow cleaning solution through the whole system to clear it out.

Circulating pump and pipework beside an old copper cylinder

When to call us

  • Radiators cold at the bottom
  • Black water when you bleed a radiator
  • The boiler is noisy or keeps overheating
  • You are fitting a new boiler onto an old system

What’s included

  • High-flow flush of every radiator, one at a time
  • Chemical cleanser and neutraliser
  • Fresh inhibitor to protect against future corrosion
  • Magnetic filter fitted if you do not already have one

Before a new boiler

Fitting a new boiler to a dirty system shortens its life and can affect the warranty. We will check the water quality during the survey and tell you honestly whether a flush is needed.

Circulating pump and pipework beside an old copper cylinder

Photographs from Green PHS jobs.

What customers say

“Technical knowledge of work required was exhibited, and competitive and comprehensive estimates were given. An energetic and efficient outfit that accommodated changes without the "sucking of teeth" that often accompanies such things.”

Barry Paul, Google review

4.8

from 201 Google reviews

Read more reviews

Radiators, underfloor heating, cylinders, power flushing and smart controls.

  • Central heating repair

    Cold radiators, noisy systems, pumps, valves and controls diagnosed and fixed.

  • Boiler installation

    High-efficiency condensing boilers, fitted neatly, with up to 15 years warranty on boilers.

  • Radiators & towel rails

    Panel, column and designer radiators, heated towel rails and TRVs.

  • Boiler servicing

    Fixed-price annual service for gas and oil boilers to keep them safe and under warranty.

Power flushing: common questions

How long does a power flush take?

Most homes take a full day, depending on the number of radiators.

Ask about power flushing

We reply the same working day. For an emergency, call 020 8050 5913 instead.

So we can check we cover your area.

Boiler make, what it is doing, any fault code, and when suits you.

We only use your details to reply about this job. See our privacy notice.

Call Lee. He picks up.

Tell him what is happening. If it is a quick fix, he will talk you through it for free. If not, we will get an engineer to you, usually the same day.

Call Lee Get a quote