Gas and heating
Power flushing
Whether this needs a licence in Ireland
No licence required
Taken from the statute below; not yet reviewed by a lawyer
Power flushing: what the job involves
Cleaning sludge, rust and scale out of a wet central heating system by pumping water and cleaning chemicals through it at speed, then adding inhibitor and usually a magnetic filter. It cures cold radiators, noisy boilers and slow heat-up caused by dirt.
Also asked for as: radiators cold at bottom · sludge in radiators · central heating flush · noisy boiler · heating system clean
How the job is usually done
- Check the symptoms: cold patches at the bottom of radiators, noisy boiler, dirty water when bleeding.
- Connect the flushing pump into the circuit, usually at the pump or a radiator.
- Circulate cleaning chemical with the boiler running, then flush each radiator in turn until it runs clear.
- Use magnets and a tap on each radiator to dislodge stubborn sludge.
- Dump the dirty water to the foul drain, refill and add inhibitor.
- Fit or clean a magnetic filter, bleed and balance the system.
Power flushing: what is included
Usually included
- Chemical cleaning and flushing of every radiator
- Inhibitor at the end
- Bleeding and balancing
Usually not included — agree it separately
- A magnetic filter, unless quoted
- Replacing radiators or valves that are seized, leaking or blocked
- Boiler repairs revealed by the flush
Materials and who supplies them
- Cleaning chemicals, inhibitor and a magnetic filter, supplied by the engineer
How long it takes
Usually a day for a typical house; badly sludged systems or older radiators can take longer.
When to book
Flush before fitting a new boiler or heat pump, and in the warmer months when heating can be off.
Power flushing: the rules in Ireland
What the official sources say, checked against them on the date shown. A summary, not legal advice — follow the link to read the rule itself.
Flushing the water side of a heating system is not restricted work, but any adjustment or repair to a gas boiler must be done by a Registered Gas Installer.
Applies to: the engineer
Energy (Miscellaneous Provisions) Act 2006; Register of Gas Installers of Ireland · rgi.ie · Checked 9 October 2026
What power flushing costs, and why
What jobs on Talqero came to
Not enough comparable jobs yet to publish a range here. Talqero shows a price range only once at least five comparable jobs, agreed prices or offers exist — a range from fewer would describe a handful of jobs, not the market. Post your job and compare the offers you get.
What affects the price
- Number of radiators
- How badly the system is sludged
- Whether a magnetic filter is fitted
- Open-vented system with a header tank or a sealed system
- Seized valves or leaks found during flushing
- VAT: building work on a home is charged at the reduced rate of 13.5% by a VAT-registered business — unless the materials come to more than two-thirds of the price, when Revenue’s two-thirds rule applies the goods rate to the whole job. Ask whether a quote includes VAT.
Paperwork to ask for at the end
- A note of the chemicals and inhibitor used and the date
- Filter warranty if fitted
Safety
- Old radiators and joints sometimes leak once sludge is removed; agree in advance what happens if they do.
- Dirty system water must go to the foul drain, not a surface water gully.
Power flushing: before you hire
Questions to ask a tradesperson
- Will you flush each radiator one at a time?
- Is a magnetic filter included?
- What happens if a valve or radiator starts leaking?
What you can do yourself
Bleeding radiators and adding inhibitor through a radiator is a householder job; a power flush needs the engineer’s pump and chemicals.
What to put in your task
- How many radiators are on the system?
- What are you noticing?
- Is there a small tank in the attic for the heating?
- How old is the boiler?
Photos that help
- The boiler and the pipes and pump near it
- A radiator with the cold area visible, or a thermal image if you have one
- Any tanks in the attic
Power flushing by county
Choose your county for power flushing close to home.
- Power flushing in Dublin
- Power flushing in Cork
- Power flushing in Galway
- Power flushing in Kildare
- Power flushing in Limerick
- Power flushing in Meath
- Power flushing in Tipperary
- Power flushing in Donegal
- Power flushing in Wexford
- Power flushing in Kerry
- Power flushing in Wicklow
- Power flushing in Mayo
- Power flushing in Louth
- Power flushing in Waterford
- Power flushing in Clare
- Power flushing in Kilkenny
- Power flushing in Westmeath
- Power flushing in Laois
- Power flushing in Cavan
- Power flushing in Offaly
- Power flushing in Sligo
- Power flushing in Roscommon
- Power flushing in Monaghan
- Power flushing in Carlow
- Power flushing in Longford
- Power flushing in Leitrim
Gas and heating
Need power flushing? Describe the job.
Post it once, free. Professionals near you reply with their own price and when they could start. You choose, and pay them directly.
Questions about power flushing
Does power flushing need a licence in Ireland?
No licence is required for this work in Ireland (source: www.cru.ie). Ask instead for references and photographs of similar jobs.
Does every system need a power flush?
No. A flush is for systems with sludge symptoms or before a new boiler. A clean system with inhibitor and a filter does not need one.
Can a power flush cause leaks?
It can reveal weak joints or corroded radiators that sludge was sealing. A good engineer checks for this and agrees beforehand what happens if it does.
What is a magnetic filter?
A small unit on the return pipe near the boiler that catches iron oxide sludge. It is cleaned at the boiler service and keeps the system clean after the flush.