The smarter way to replace your boiler

  • Get FREE Quotes today
  • Compare quotes & save money
  • Over 5,000 engineers across the UK
Tell us about your job
Get Free Quotes

Removing Central Heating Sludge – a How to Guide

As boilers get older, many of us expect them to slow down and not work as efficiently before eventually paying to have them replaced

However, if your boiler is struggling to heat your home and is younger than ten years, then radiator sludge could be the culprit. Rather than paying out more than you need to get an entirely new system, take a moment to find out more about radiator sludge and how you can get rid of it!

Radiator Sludge – What is it?

If you’ve never heard of radiator sludge, then don’t worry – it’s just a build-up of dirt and rust that gathers within your central heating system, combining into a sludge that can build up and start to clog your radiators.

Why is Radiator Sludge Bad?

As the sludge grows in size, it can cause your radiators to have cold patches or stop them from being able to heat up altogether, meaning that you are paying to heat water that cannot pass through your system and warm up your home! 

If it is left for some time without being dealt with, it can also clog the heat exchanger, radiator valves, pipework and other components that are all expensive to fit. It can also be dangerous if left, as the pump will keep working to send water, putting too much pressure on your seals and causing them to blow. 

The Key Signs That You Have a Sludge Problem

Rather than letting radiator sludge become a problem, there are a number of ways you can identify that there is a build-up, including:

  • Your radiator doesn’t warm up to the required temperature even on the highest setting
  • Some of your radiators have cold or lukewarm spots
  • Your radiator is only hot at the top
  • Your radiator may not get warm at all
  • Your boiler makes club king and clanging sounds
  • You may be bleeding your radiators on a regular basis and see dirty water escaping
  • Your pump keeps overheating and may have too much back pressure
  • Your seals have blown, causing a leaky circulator pump
  • Your boiler has stopped working because the parts have clogged up
  • Your pipes are hot to the touch, but your radiators are cold
  • You notice that your valves break regularly
  • Your flow pipe is sending hot water to your system, but the return pipe is cold

How You Can Confirm a Sludge Build Up

If you’ve noticed one or more signs of a sludge build-up, then you will want to confirm that you are correct before paying to have it fixed. Luckily, there is a quick and simple way to confirm your suspicions that will only cost you the price of a bleeding key! 

Get your radiator key, clean cloth and a container and head to the radiator you are worried about. Put the container under the valve with the cloth to catch any water that may escape, and then slowly turn the valve until water begins to come out of the radiator, letting some drops reach the container and cloth before closing it again. 

Once you have collected the water and closed the valve, you can check whether the water is clean or dirty. If it is dirty, then you could have a sludge build-up. It is wise to continue the test on all your radiators to ensure that the system is fully bled and then put the heating on to see if the radiators warm up properly. If they don’t, but the pipes are hot, then you can be certain that sludge is the problem, and you will need to get it removed to resolve the issue.

How to Remove Radiator Sludge

So, you’ve worked out that you have radiator sludge in your system and want to remove it? Take a look at some of the best ways listed below:

  1. Manual Flush – the first step is to try and flush the system yourself by letting your radiators cool down and then turning off the thermostatic and lock shield valves on your radiators. You can then disconnect the valves and open the bleeding valve before tipping the radiators and letting the sludge run out. Next, connect a hose to the radiator and run water through it until it runs clear before refitting the radiator. Repeat for each radiator in your property.
  2. Power Flush – if your manual flush doesn’t get rid of the problem, then you are more likely to have a big build-up of sludge that has been there for a while. In this case, you will need to pay an engineer to complete a power flush for you, sending strong chemicals through your system to dislodge all the sludge. This service can cost anywhere between £300 – £800, depending on your location and the number of radiators that need to be flushed.
  3. Replacement Radiators – if a power flush is too expensive and you only have a couple of problem radiators, then replacing them may be the next best idea. New radiators are not too expensive and will offer a boost in efficiency than an older, blocked model. 

Once you have resolved your sludge problem, it is wise to schedule an annual boiler service to help you keep on top of maintaining your system. During your service visit, the engineer will be able to advise you on whether there are any signs of a sludge build-up, helping you to resolve the issue before it becomes a bigger problem.

How to Avoid Radiator Sludge From Building Up

Once you have removed your radiator sludge, it is a good idea to use preventative methods to stop it from occurring again. The best way to do this is to install a scale reducer which works to capture particles from the water, the perfect solution when you live in a hard water area. 

In addition, installing a magnetic sludge filter is also important as it works to remove any debris from the system, keeping the water flowing cleanly and easily from the flow pipe to the return pipe. Both of these preventative tools will cost a couple of hundred pounds, but they could save you time and money, stopping your boiler from breaking long before it should.

Removing Sludge Before Installing a New Boiler

Finally, if your boiler has been damaged and needs to be replaced, it is sensible to get the sludge removed before installing your new system. Many consumers think that sludge build-ups just impact the functionality of their radiators, but the reality is that it puts a lot of extra pressure onto the boiler, making it work harder than it should. If you don’t remove the sludge before your new boiler gets to work, then you may end up needing to get it repaired or replaced in the very near future.

If you are keen to get support with your sludge build up or want to speak to a professional about having a new boiler installed, then fill in your details on our quotation form to find the best provider in your area. At Boilers Prices, our business is to help you get the solutions you want at the prices you need – let us help you today!