Sludge removal from radiators is a recommended maintenance measure for certain types of radiators. This practice is generally recommended to prolong the life of the devices and avoid loss of performance over time. But is it really useful? What does sludge removal really consist of? When, why and how to practice it? What price when calling on a professional? Our answers in this file.
What is radiator sludge removal?
While removing sludge from radiators is a common and recommended practice, not everyone knows exactly what it consists of. Sludge removal is a cleaning action that aims to eliminate the sludge that naturally accumulates in radiators.
This sludge is formed over time by an accumulation of impurities, limestone, bacteria and by the corrosion of metals which gradually oxidize in contact with water. This sludge is deposited in the lower part of the radiators, this is called sludge. However, stored in this way, they disrupt the proper functioning of the devices, which lose performance and wear out much more quickly. It should indeed be known that sludge hinders the performance of equipment and can lead to overconsumption of energy of the order of 10 to 20%! Sludge removal therefore simply consists of eliminating this sludge.
Of course, not all types of radiators are affected by sludge removal. It applies to systems that operate through a hydraulic central heating circuit. This therefore concerns boilers (gas, oil, wood and pellet), heat pumps and combined solar systems.
There are two sludge removal techniques:
- per machine : this machine sends pressurized water into the circuit to remove sludge from the radiators.
- By product : a sludge remover is injected into the circuit and acts for 24 to 48 hours. It is used to loosen the mud particles in order to allow them to be evacuated by rinsing or by draining the radiators.
Why should radiators be unblocked?
As we have said, sludge removal is used to eliminate particles that naturally accumulate in radiators and form sludge. However, these muddy materials impact the efficiency of radiators, reduce their energy performance and increase heating bills.
Sludge removal has many advantages:
- It facilitates the good circulation of water in the heating circuits.
- It maintains the good performance of the heating system.
- It prevents the heating network from operating at full power to compensate for its lower efficiency due to the presence of sludge, which preserves its lifespan.
- It enables energy savings of up to 15% on average.
- It avoids the effect of premature wear of the heating device.
- Heating comfort is much higher.
In summary, sludge removal from radiators is indeed a useful and important procedure. However, you should know that if the procedure is simple with new installations, the oldest ones can be weakened, especially when the accumulated sludge clogs certain leaks that must then be filled in another way.
When should you unclog your radiators?
It is recommended to remove sludge from radiators before the heating season, ideally during the fall. Nevertheless, if the radiators are well maintained, it is not always useful to carry it out every year. Some pros recommend flushing a relatively new, healthy device every 5-10 years. An annual check is recommended mainly on older installations.
Best to do a test. Simply bleed your radiators and observe the liquid that flows out. If it is clear, it is clean water and all is well. If it is loaded with impurities or sludge, it is time to clear the network. Likewise, if you notice that part of your radiators remain cold to the touch when they are running or that they are particularly noisy during their operation, you should consider sludge removal.
On the other hand, if you plan to install a new heating appliance on your circuit, we recommend that you remove the sludge beforehand. This will allow you to start over with a clean circuit and avoid weakening your new boiler or your brand new heat pump from the start.
How to unclog your radiators?
Sludge removal can be done by you or by a qualified professional.
How to unclog your radiators yourself?
To remove sludge from your radiators, follow these steps:
- Bleed your radiators to remove accumulated air.
- Start by emptying your heating circuit.
- Close each radiator one by one.
- Connect a garden hose to the faucet and open the boiler isolation valves.
- Turn on the water supply at the other end of the hose and observe the condition of the water flowing out. Wait until it is clear to stop.
- Your radiators are then clean and free of sludge. All you have to do is put the circuit back in place.
You can also use a chemical sludge remover to inject into the circuit. This will loosen the sludge and release the particles in suspension to better eliminate them during emptying. Count between 200 and 300 euros for the purchase of a sludge removal kit.
Entrust the sludge removal of your radiators to a professional
If you do not want to take care of removing sludge from your radiators, you can entrust this task to a qualified and competent professional. Count between 400 and 800 euros to involve a pro. The price varies from one company to another, but will essentially depend on the size of your heating network and the technique used.