A Quick Guide To Power flushing

Power flushing is a process that cleans your central heating system. It's used to remove debris, sludge, and rust that accumulate over time and can cause your radiators to become less efficient. Here's a step-by-step guide on how to power flush your radiators.

STEP 1 - Turn Off The Central Heating System

Turn off your central heating system to prevent it from running while you're working on it.

STEP 2 - Set Up The Power Flushing Unit

Attach the power flushing unit to your central heating system. This is usually done by connecting it to the circulator pump or one of the radiators in your system. You'll also need to connect a hose to the power flushing unit so it can dispose of the dirty water.

STEP 3 - Fill The Power Flushing Unit With Water And Cleaning Chemicals

Attach the power flushing unit to your central heating system. This is usually done by connecting it to the circulator pump or one of the radiators in your system. You'll also need to connect a hose to the power flushing unit so it can dispose of the dirty water.

STEP 4 - Start The Power Flushing Unit

Turn on the power flushing unit. The cleaning solution will begin to circulate through your radiators and central heating system. The power flushing unit should have a pressure gauge; if the pressure drops suddenly, it may indicate a blockage in the system.

STEP 5 - Check The Radiators

As the power flushing unit is running, check each of your radiators. They should all be heating up evenly. If one radiator is colder than the others, it may have a blockage that needs to be removed.

STEP 6 - Flush The System

Once the cleaning solution has circulated through the system for a sufficient time (usually around 30 minutes to an hour), it's time to flush out the system. This involves letting fresh water into the system while draining the dirty water out. Continue this process until the water coming out of the system is clean.

STEP 7 - Disconnect The Power Flushing Unit

Once the water running out of the system is clean, turn off and disconnect the power flushing unit.

STEP 8 - Reconnect the System and Refill with Water

Reconnect any parts of the system you disconnected to install the power flushing unit. Then refill your central heating system with clean water.

STEP 9 - Add Inhibitor

Once the system has been flushed, refilled, and reconnected, add a corrosion inhibitor to the system. This chemical will help prevent rust and sludge from forming in the future, extending the life of your radiators and heating system.

STEP 10 - Turn Your Central Heating System Back On

Finally, turn your central heating system back on. Check all the radiators to make sure they're working properly and heating evenly.

Frequently asked questions

What is Powerflushing?

Powerflushing is purely and simply a way of removing the rust that slowly builds up in your heating system and boiler over time. Water, chemicals, powerflush equipment and an experienced plumber are used to remove the rust and sludge from your central heating. The flow of the machine is reversed from time to time using special three-way valves attached to the flushing pump. This is an extra step to help clean the pipes and radiators to remove cold spots.

Do You Provide A Guarantee?

Yes, we provide a full guarantee. At the end of each job we will post a certificate to you that guarantees your power flush.

Does The Engineer Need To Be Gas Safe Registered?

No. A power flush can be undertaken by an experienced and knowledgeable engineer as we do not touch the gas supply or exhaust vent system.

My boiler bangs or cuts out

The reason that happens is generally one of two things:

1. Your pump has failed or is stuck. The water can’t circulate and therefore the water that is in the heat exchanger will boil very quickly. In some older boilers in particular it takes a while for the thermostat in the boiler to turn the gas off. In modern condensing boilers the thermostats are more sensitive and will extinguish the boiler flame quickly.
2. There is a blockage in the main flow or return pipework, or with the water ways in the boiler heat exchanger which is either completely or partially blocking the flow of water through the boiler – so the water in the boiler starts to boil and make steam again. Hence the popping, hisses and bangs.

Where does the rust in my heating system come from?

If you have seen someone else’s system power flushed you will know what an amazing amount of rust and radiator sludge can come out, in all shapes and sizes. But, contrary to popular belief the vast majority of the sludge that you see does not come from your boiler. Most non-condensing boilers (those installed before 2006) have cast-iron heat exchangers and they, by and large, do not rust. The vast majority or rust and/or sludge in your heating comes from the radiators themselves as they are made from mild-steel.

Why does rust form in the first place?

Water is made of hydrogen and oxygen (one part H and two parts O = H2O). Oxygen is highly reactive and is always looking for somewhere to latch on to instead of the Hydrogen molecule. So, any time it comes across a piece of iron that is ‘bare’, i.e. unprotected, it is going to latch on to that and makes rust (most often Fe2O3). And that’s where rust comes from. Power flushing radiators will remove that.

How do I protect my heating system after it is cleaned?

Once you have had a specialist in to do the work for you, the best way of protecting your system is to have the heating system regularly topped upped with corrosion inhibitor. These stop the rust forming by adding a protective molecule to any exposed bare iron. That molecule (most often a form of another metal called molybdenum) parks in the place that the oxygen molecule would want to be. And the result is no rust. The only caveat to this is if your heating system has a design flaw in it and is pulling in fresh water all the time.

Why powerflush?

Yes, there are other ways of cleaning your central heating system, but they are nowhere near as effective as using a the right machine when it is used by a competent and experienced heating engineer. You can add any chemical cleaner in to the system, leave for up to four weeks (Warning:careful here if you have micro-bore pipework) and then open up the system drain-cocks and let the water run out.
When you do that the only force moving the water out of the system is gravity and that will not pick up any larger bits of rust. Those will be left in nooks and crannies.

Can A Power Flush Fix Cold Radiators?

Yes, a powerflush can fix cold radiators. Particularly if they are cold at the bottom.  Sludge collects in a hump in the bottom of radiators so if your radiator is cold in the middle at the bottom it can be a sign that sludge is building up.  Other places that sludge commonly builds up are in the airing cupboard and at the manifolds in microbore systems.

Can micro-bore pipework be powerflushed?

The short answer is “Yes, it can”, but with a great deal of care. 10mm microbore systems need to be approached in a very different way to standard sized pipework. 8mm microbore systems need a lot of careful thought before flushing out. Microbore pipework was first commonly introduced in the 1970’s in an attempt to reduce the amount of copper needed to install a heating system.

We're here to help

Decided to power flush your system can be a little daunting. We've got a team of specialists ready to help.