Power flushing costs: How much you can expect to pay

When your central heating needs a deep clean, you’ll need to think about power flushing costs. Bleeding a radiator and an annual service are two essential maintenance options to help keep your heating system running efficiently. But not the only ones.

You will need a power flush to help get rid of any rust, sludge and residue that has accumulated over the years. This will give you a fresh clean central heating system that will get it working like new and help keep down your energy bills.

Here we look at what you can expect to pay for a small space through to a large house, how often a power flushed is needed and an alternative option that could cost you less.

How much does power flushing cost?

The cost of a power flush will depend on the size of the home and the number of radiators. But, Gordon Chalk and Alan Houghton of MDs at Next Level Underfloor Heating and Screed Solutions share that it is the number of radiators that is the key to cost, “The number of radiators will usually determine the final cost more than the type of property but there are a few exceptions.”

Here they break down the typical prices for different size homes and number of radiators.

• Two bed house £300-£400 (6-8 radiators)
• Three bed house £400-£550 (8-10 radiators)
• Four bed house £550-£700+ (10+ radiators)

Obviously the more radiators the more flushing is needed, meaning a higher price. Chalk and Houghton add, “Flats are usually cheaper as they have fewer radiators and are more compact. However other factors like system complexity and accessibility can affect the price.”

Gordon Chalk and Alan Houghton

Working in the industry for over 15 years Gordon and Alan's mission is to help property owners get warmer and more comfortable with underfloor heating and proper floor screed.

Additional costs to power flushing

Alongside the cost of a power flush there are a few other costs that may occur. These are optional, but can help ensure that your heating system will be running efficiently. Chalk and Houghton reveal the typical additions.

• Magnetic filter installation Installing a magnetic filter during the flush (highly recommended for better results) will add £100-£150.
• System repairs If radiators or system components are heavily corroded or blocked additional work may be required and will add to the cost.
• Boiler servicing Some companies include boiler servicing but if not then this will add £60-£100.

FAQs

How often do I need to spend money on a power flush?

This will depend on different factors but as a general guideline you should consider getting a power flush performed every 5-6 years to make sure your heating system is running efficiently.

However, if you are installing new radiators, this is a good time to get a power flush done at the same time. This will get rid of any old residue left behind by the old radiators, ensuring that the new radiators will be working in harmony with the rest of the system.

The same principle applies if having a new boiler installed. For a new boiler's guarantee to be effective the manufacturer will insist that it is being installed onto a clean system. You’ll need the services of a registered gas engineer or plumber to perform the power flush.

Is it cheaper to have fewer radiators included in a power flush?

Unfortunately you can't make power flushing cheaper by doing fewer radiators. A power flush looks to get rid of any debris from an entire heating system. This includes radiators, pipes and the boiler, so it makes no sense to leave out a radiator or two.

It is unusual to exclude a radiator from a power flush and Chalk and Houghton wouldn’t recommend it. “Flushing part of the system (e.g. the downstairs radiators) will result in uneven heating and future problems. If you try to power flush only part of the system you won’t get the full benefits as debris can circulate back through the unflushed areas.

If you do remove a radiator before a power flush you need to flush the radiator separately and ensure it is clean before replacing.

Are there any alternatives to power flushing?

There is only one other alternative to power flushing which is chemical flushing. This is the process of adding cleaning chemicals to a heating system and allowing them to circulate for a few days or weeks, eventually flushing the system out. The process to add the chemicals takes a lot less time than power flushing.

But, chemical flushing is not as powerful or as effective as a power flush as Chalk and Houghton share, “Chemical flushing is a less intensive process than power flushing and is generally cheaper.” So how much does it cost? “For a two bed house expect to pay £200-£300, while a four bed house will cost around £400.” They add, “Prices rise with the number of radiators but this method is less effective for heavily blocked systems.”

Chalk and Houghton suggest that chemical flushing is, “For maintenance only, not for heavy sludge or blockages.” They add, “Some systems may need a chemical flush followed by a power flush if the build up is severe which will add to the cost.”

Can all heating systems be power flushed?

Most heating systems including combi, system and condensing, can be power flushed. But not all as Chalk and Houghton explain, “Electric heating systems (storage heaters) can’t be power flushed as they don’t circulate water.”

But are there any differences in the cost for different heating systems? Chalk and Houghton share, “Most companies charge the same for all system types but more complex systems or older properties may incur a slightly higher fee due to the extra work involved.”

Power flushing is part of keeping your heating system efficient and cost effective. Check out what you should by paying in our central heating costs per hour guide. For more tips on saving energy in the home check out our Most economical way to use central heating guide and How to fit thermostatic radiator valves for more efficient heating.