Power Flush Price

How much to power flush a central heating system?

Last Updated: 23 February 2020. If your central heating system is not working to its full capacity, is making unusual noises or is slow to heat up, it may benefit from a professional power flushing service. This technique is able to remove any build up inside the system itself, effectively eradicating sludge, rust and other contaminants from the pipes, coils, heat exchangers and radiators to restore your central heating system to its full power. A power flush can not only improve the quality of heating throughout your home or commercial premises, but can also help to lower heating bills and preserve the lifespan of your system. Following this treatment, your radiators will not only heat more rapidly, but your central heating system will be far more cost efficient, heat will be distributed much more evenly between rooms and your boiler will experience less stress. Further down the page you can read about “How Does A Power Flush Work?”, but please read on here.

Power flushing is the best way to ensure that your central heating system does not fail prematurely, which can occur if there is excess sludge blocking your system. If you are installing a new boiler, it is also recommended that you carry out a full power flush in order to ensure that your system is in the best possible working order before installing the brand new equipment, otherwise your expensive new boiler could be false economy.

What Price Power Flushing?

Power Flush Price SavingIf you have decided that a power flush could be the answer to your central heating problems, you are probably wondering what is the cost and how much you can expect to pay that will end up saving you money in the long run?

The price of a power flush will depend upon the type of business that is carrying out the procedure as well as the area of the country in which you live. Some areas are naturally more expensive than others, and the size of the plumbing company is another important factor in the cost of a power flush. While there are natural variations in price, London is the most expensive part of the country in which to arrange a power flush, while the north of the country is around £50 to £100 cheaper, depending on region and business size. Click straight to the Cost of a power flush table.

As might be expected, a larger company with a greater number of employees will ask for higher prices for a full power flush, while a smaller operation with just one or two workers will generally command lower costs.


Overall, taking a number of quotes from several different sized companies and across the length and breadth of the country into account, the average price of a power flush is £410, with the lowest quotations coming in at around £300 and the highest being around £550. If you are considering arranging a power flush for your central heating system, you should take the time to get quotations from a wide range of businesses that provide the service in your local area to ensure that you get a competitive quote. Of course, if you have a larger property or a system that is in especially poor condition, you can expect the price to rise.

Of course, price is only one thing to consider. The quality of the job is just as important and one way to find out who knows what they are doing to is look for reviews of previous powerflushing work.

Symptoms Of A Heating System That Needs A Powerflush

Power flushing is a method used to clear sludge from main heater pipes, radiators, coils and heat exchangers. These are aspects where scale and rust can gather, the signs are typically:

Cold areas on radiators, even after bleeding

Takes a long period of time for radiators to heat up

Noisy boiler

Radiators requiring regular bleeding

Inefficient central heating unit

Obstructed central heating system


Once a power flush is complete, you can expect the following benefits:

Radiators and pipes will get hotter quicker.

More effective system.

Less tension on the boiler.

Increased life of the boiler.

Heat will be dispersed more equally throughout the home.

Central heating boilers can fail early if there is excessive sludge in the system, modern-day condensing boilers are much more sensitive so it’s suggested to have a full system flush before setting up a new boiler. There is no point in spending money on an expensive appliance that may fail early because of excessive sludge build up in the system!

If the system hasn’t been recently power flushed, you need to also check the guarantee on any brand-new boiler/s as a lot of makers will not accept an insurance claim.

If a new boiler is being set up and/or if the system hasn’t been cleaned for a long time, we would advise property owners to have this work done. When working efficiently, the system must run more economically, conserving you cash.

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As you can see from the table above, the typical cost of a power flush for two-bed house is‚¤ 410.00.


How Does A Power Flush Work?.

During the preliminary assessment, your chosen specialist should have explained the work involved and the expected cost savings.

Prior to beginning with the work your trades-person needs to check the boiler for correct operation and all the radiators for cold spots, ideally taking the temperature of each radiator. A sample of the water ought to also be taken– for comparison.

When all radiator valves have actually been removed or opened, dust sheets placed over carpets etc, the power flushing machine can be connected.

The first flush involves a chemical power flush of the entire system consisting of a reverse circulation, this normally takes around 20 to 60 minutes. Each specific radiator is then flushed individually, starting with the coldest rads. A rubber mallet can be used to relax any scale/sludge. This procedure is then duplicated across all the radiators.

A 2nd flush happens throughout all radiators separately.  The second part of the process involves adding cleaning chemicals which have been specifically made to suit your boiler. The fluid is then reversed periodically until all cold spots have been removed from the system.  A rubber mallet is also used to gently knock the bottoms of the radiators to free any bits of rust that are reluctant to leave the system.

A final flush of the system is then carried out using fresh water whilst checking the PH & TDS readings of the water being discharged. (All chemicals are neutralised before being removed safely).

An inhibitor is added to the water and distributed through the system for 15 minutes. A sample is then taken and tested, more inhibitor can be included if needed. The TRVs (thermostatic radiator valves) are then refitted and set to the optimum setting as the system is ‘balanced’).


General Procedure For Power Flushing Radiators/Boiler.Power flush procedure

Record temperature of radiators (so we know which are heavily clogged).

Record TRV settings on each radiator.

Take water sample.

Open all valves and get rid of TRVs.

Bridge any valves or equipment that may avoid reverse circulation i.e pump.

Separate boiler.

Take precautions to protect carpets etc

. Link power flushing system.

Carry out secondary and primary flushes dislodge stubborn sludge with rubber mallet or vibrating tool.

Remove any stubborn radiators and manually tidy with tube. refit rads.

Take temperature level of individual rads and compare with original radiators.

Test water.

Include inhibitor (likewise neutralizer depending on system) and test.

Re set up TRV’s and any other valves and balance the system.


How Long Does a Power Flush Take?

This depends on how might radiators there are as well as how much sludge is inside them. For a normal 2 bed home presume 4-6 hours. If your trades-person has to get rid of great deals of radiators and by hand flush each one with a power washer and then refit them then assume longer!


Q: Do radiators need to be gotten rid of?

A: In some cases, compressed sludge can only be removed by removing the rads and manually cleaning them with a powered pressure washer/hose.

Q: Instead of having the system flushed can I not just install an irreversible magnetic filter?

A: Sludge caught in the rads will not distribute so won’t be caught in a magnetic filter unless a power flush is finished. These filters just catch loose sludge, not sludge which is compressed.

Q: I have had my rads consistently flushed however they keep obstructing up with sludge, what gives?

A: If your heating system is permitting oxygen into the pipework, this will speed up the rust of the pipes/rads resulting in excess and frequent advancement of rustic sludge. We suggest you have your heating unit checked by a certified engineer prior to you flush the system again.

Q: How typically ought to I have the system power flushed.

A: If done correctly you should not have to have the system flushed for 10+ years but if the rads/pipework are rusting and producing fresh sludge then it have to be flushed faster. Having the appropriate levels of inhibitor in the system and having this checked/topped up annual will assist. Make sure you take down which brand of inhibitor has been utilized, otherwise testing will be undetermined (some installers leave the empty bottle behind).

Q: Can all kinds of central heater be flushed?

A: Yes, all kinds of heating systems can be flushed.

Q: Are TRV (rad valves) a concern?

A: No, the pins can get stuck as an outcome of the sludge however this is quickly inspected and corrected.

Q: I have received a quote for 150, is this a fair price/cost?

A: For this rate we would not anticipate a total and comprehensive power flush, although water may run clear after a power flush it may be because the water is flowing over compacted sludge. Removing this compacted product takes some time as it often involves tapping the rads or eliminating them and by hand cleaning them. We would suggest  300 –  450 for a two bed home as a guide price, depending on area. Prices do differ certainly, some smaller firms may charge below  300 while big business like British Gas have actually been understood to charge well above  600.

Q: Should I have the main heating system refilled every year and drained pipes?

A: No. This will only include oxygen and other pollutants to the water, this will speed up the deterioration.

Q: What is the sludge really made from?

A: It is mainly rust that rusts from the metal pipes and radiators, however likewise contains impurities from the water.

Video (courtesy of Fernox)

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