Microbore Central Heating Powerflush a Specialist Service

Most microbore systems can be successfully powerflushed, but not all. The key factor is the condition of the pipework. Copper microbore pipes that are structurally sound — even if they’re old and sludged up — respond well to a professional powerflush. Where systems may not be suitable are those with heavily corroded or thinning pipework, or where plastic push-fit microbore fittings have degraded significantly. We always assess before starting work and will give you an honest opinion. We won’t take your money for a job we don’t think will deliver results.

The easiest way to tell is to look at the pipes going into your radiators. If they’re very thin — around the width of a pencil (8mm or 10mm in diameter) rather than a standard thumb-width pipe — you almost certainly have a microbore system. Many homes built in the 1970s and 1980s, and the 90’s were fitted with microbore systems as standard. You may also notice a central manifold (a metal box or pipe junction) under floorboards or in an airing cupboard, with individual pipe runs going off to each radiator.

Almost certainly, yes. This is one of the most common situations we deal with. A new boiler fitted to a sludge-blocked microbore system will struggle from the start — it can’t fix the underlying blockage, it can only try to push water through it. The result is poor heat output, short cycling (the boiler turning on and off rapidly), and unnecessary wear on the new boiler.

A powerflush of the system clears the blockage and allows the boiler to work the way it was designed to.

Yes We are fully trained qualified and certified and insured to work on gas appliances, our gas-safe number is 555837

Longer than a standard system flush, typically. A straightforward microbore system with moderate sludge build-up might take 6 to 8 hours. A heavily blocked system — particularly one where individual pipe runs are almost fully restricted — can take considerably longer. We’ve spent upwards of 10 hours on a single property when that’s what it took to get every radiator working properly.

We don’t charge by the hour, and we don’t leave before the job is finished.

In many cases, yes. A radiator that has been cold for years due to a blocked microbore feed pipe can be restored to full heat output after a thorough powerflush. There are instances where a pipe run is so heavily blocked that flushing alone isn’t sufficient — in these cases we’ll discuss options with you, which might include isolating that run or accessing the manifold to clear the blockage directly.

What we won’t do is tell you it’s worked when it hasn’t.

Yes — and the most important step is ensuring a quality corrosion inhibitor is correctly dosed in the system after the flush. We always add inhibitor as part of our standard service. Beyond that, fitting a magnetic filter (such as a Magnaclean or Fernox TF1) to the system will capture any future particles before they circulate. We can advise on the best option for your system. Annual inhibitor checks are also recommended.

Very likely. When a boiler is working against a restricted microbore system, it overheats rapidly because the water it’s trying to heat isn’t flowing away fast enough. This causes kettling (a rumbling, boiling sound), followed by the boiler cutting out on its overheat stat as a safety measure. Once it cools down, it fires again — and the cycle repeats. This is known as short cycling, and it puts enormous strain on the boiler. A powerflush to clear the restriction is usually the fix.

It’s a common misconception, and understandable — microbore systems do require more care, more time, and the right equipment. Some engineers prefer not to take on microbore work because it can be unpredictable and time-consuming. What isn’t accurate is a blanket statement that it can’t be done. We’ve successfully powerflushed hundreds of microbore systems across the North West, including systems that other engineers had given up on. If you’ve been told your system is beyond help, it’s worth getting a second opinion from someone who specialises in exactly this type of work.

Often, yes. A pump that’s making unusual noises — grinding, humming loudly, or surging — is usually struggling against the resistance of a sludge-restricted system. Once the blockage is cleared and water can circulate freely, many pumps settle down and run quietly. In some cases the pump itself may have been damaged by running against a blocked system for too long, in which case replacement may be needed. We’ll be upfront with you about what we find.

We’d recommend being at home, yes. The process takes most of the day, and we’ll want to keep you updated on what we find as we go. We always show customers the state of the water coming out of the system — before and after — so you can see for yourself the difference the flush has made. It also means we can discuss anything unexpected we come across, rather than making decisions on your behalf.

if you are a landlord or not able to be at the property, then we can video the work before and after and can keep you up to date on the process.

Yes. We offer a 100% satisfaction guarantee on all our work. If you’re not happy with the outcome, we want to know about it and we’ll work to put it right. We won’t take payment for a job we haven’t delivered on.