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HIU Powerflush London — Plate Heat Exchanger Descale

Is your HIU producing lukewarm water or running noisily? Sludge and scale in the plate heat exchanger could be the cause. Collide Group's specialist HIU powerflush service removes contamination safely and restores your unit's performance.

Sludge & Scale Are Killing Your HIU

London's hard water and the iron-rich water in many heat networks creates a perfect environment for limescale and magnetite sludge to build up inside your HIU's plate heat exchanger. Once it starts blocking, performance falls fast.

  • Lukewarm or cold hot water
  • Reduced flow at taps and showers
  • Unit running continuously at high temperature
  • Noisy or vibrating HIU
  • Higher than expected energy charges
  • Previous servicing showing blocked strainers repeatedly

A Full Powerflush — HIU-Safe

Standard domestic powerflush machines are too aggressive for HIUs. We use methods and chemicals designed specifically for Heat Interface Unit plate exchangers — effective but safe for seals and sensors.

  • Pre-flush flow and temperature performance baseline
  • HIU-safe chemical dosing and circulation
  • Plate heat exchanger descale and flush
  • Primary strainer clean and check
  • Post-flush performance verification
  • Inhibitor treatment to prevent reoccurrence
  • Written report with before/after readings

Brands We Cover

DanfossSAVSwitch2Alfa LavalCaleffiHeatwebThermal IntegrationRedan

The Benefits

Restored Hot Water

Most residents notice an immediate improvement in water temperature and flow rate after powerflushing.

Lower Energy Use

A clean plate exchanger transfers heat efficiently, reducing the unit's run time and primary energy draw.

Extends HIU Life

Removing scale and sludge prevents premature failure of the plate exchanger and surrounding valves.

“Residents in our Greenwich block had been complaining of lukewarm water for months. Collide powerflushed the HIUs and within a day the complaints stopped.”

— Property Manager, Greenwich

HIU Powerflush from £250

Prices start from £250 inc VAT. Heavily contaminated units or block contracts may vary — we always provide a written quote first.

Book a Powerflush

Frequently Asked Questions

What is an HIU powerflush?
An HIU powerflush uses high-velocity water and specialist chemicals to remove sludge, scale and corrosion debris from the plate heat exchanger and secondary circuit of your HIU, restoring flow rates and heat transfer efficiency.
How much does an HIU powerflush cost?
An HIU powerflush starts from £250 inc VAT. Final price depends on the degree of contamination and the HIU brand. We provide a free quote before starting work.
How long does a powerflush take?
A standard HIU powerflush takes 2–4 hours depending on the severity of the blockage and the brand of HIU.
How do I know if my HIU needs powerflushing?
Signs include lukewarm hot water, reduced flow rate, noisy unit, slow heat-up times, and higher-than-usual energy charges.
Is powerflushing safe for my HIU?
Yes — our engineers use HIU-safe chemicals and methods designed not to damage seals, gaskets or sensors. Standard domestic powerflush machines are too aggressive for HIUs.

Book an HIU Powerflush Today

Restore your HIU's performance. Free quotes, transparent pricing, specialist engineers.