All central heating systems have the potential to start corroding from the time of installation and commission. So how do you protect yours?

To help reduce the rate of corrosion which happens when the water mixes with the metal inside your pipework and radiators, you have two options: the installation of inhibitor which will help reduce the rate of corrosion, and the installation of a magnetic filter which attracts and removes harmful debris from your system.

It’s important to note that for the most effective results, both should be used together in tandem, with installation directly after a powerflush of your system. Whether it’s a new boiler install or not.

Black sludge will move around your central heating system before finally settling at the bottom of radiators and pipework, usually on lower levels such as the ground floor or basement. Because of this sludge build up, water flow becomes restricted and your system less effective – the water cannot reach the bottom of radiators, therefore, they stop heating up altogether.

Chemical Inhibitor

A chemical inhibitor works by disrupting the process that forms magnetite in the first place. But don’t confuse this with being a fool-proof method. It doesn’t actually prevent corrosion or the formation of sludge, it instead slows the process down, prolonging the life of your boiler and central heating components.

Inhibitor needs to be topped up at regular intervals to keep it working and some boiler manufacturers now require its presence to avoid invalidating the warranty.

Magnetic Filteration

When ferrous materials corrode, they produce iron oxide – often seen as rust. This makes up the vast majority of the black sludge that blocks radiators and pipework, often settling at the bottom; hence why blocked radiators heat at the top but remain cold at the bottom – the water cannot pass through the blockage of sludge.

A magnetic filter will attract and collect this sludge and trap it before it reaches your boiler. This prevents even more build up and loose sludge from travelling around your system.

However, magnetic filters will not get rid of all debris. They cannot catch any corrosion of copper, zinc or aluminium, which is why they are best used with an inhibitor, rather than as a standalone solution.

Prevention, Not Cure

It’s important to note that chemical inhibitors and magnetic filters are both preventative measures to avoid sludge build up, rather than acting as a cure. While they can both help prevent further problems, neither are capable of removing sludge that’s already settled in radiators or pipework.

The only truly effective way to cure problems caused by sludge build up is to have a powerflush carried out, and then the installation of both these methods to prevent further build up.

A powerflush will force a large volume of water through the system quickly, at a low pressure. The water flow will periodically change direction, to create some turbulence, which in turn stirs up settled sludge, allowing it to be drained from the system.

Depending on the company carrying out the work, they may use chemicals to help break down stubborn sludge during the powerflush, or they may also use a magnet to help catch the sludge as it’s passed through the system.

By installing inhibitor and a magnetic filter to a clean system, you are prolonging the life and efficiency of your boiler and entire central heating system, resulting in lower energy bills and lower maintenance costs.