If you live in a hard water area, limescale can build up inside pipes, boilers, hot water cylinders and household appliances. A scale inhibitor can help reduce the formation of limescale without chemically softening the water.
Two common types are magnetic scale inhibitors and electrolytic scale inhibitors. While both are designed to reduce limescale build-up, they use different treatment methods and have different maintenance requirements.
In this guide, we'll explain what scale inhibitors are, how magnetic and electrolytic scale inhibitors work, compare the differences between them and help you decide which type may be suitable for your plumbing or heating system.
What Is Hard Water?
Hard water contains naturally occurring minerals, mainly calcium and magnesium. When hard water is heated, these minerals can contribute to the formation of limescale deposits on heating elements, inside appliances and along pipework.
Common signs of hard water include:
- White limescale deposits around taps and showers
- Limescale inside kettles and other appliances
- Reduced water flow caused by deposits
- Build-up around heating elements
- Increased maintenance requirements
A scale inhibitor is designed to help reduce the formation or adhesion of limescale caused by these minerals.
What Is a Scale Inhibitor?
A scale inhibitor is a device designed to reduce the formation or adhesion of limescale caused by minerals such as calcium and magnesium in hard water.
Unlike a water softener, a scale inhibitor does not remove these minerals from the water. Instead, different types of scale inhibitor use different treatment methods to influence how scale forms as water passes through the system.
Common types include magnetic scale inhibitors and electrolytic scale inhibitors.
How Do Magnetic Scale Inhibitors Work?
A magnetic scale inhibitor is designed to influence the behaviour of scale-forming minerals as water passes through the treatment device.
The aim is to reduce the formation or adhesion of hard limescale deposits within pipework, heating systems and appliances.
Magnetic scale inhibitors typically require no electricity and do not add chemicals to the water, making them a simple option for many domestic plumbing systems.
Benefits of Magnetic Scale Inhibitors
- No electrical supply required
- No chemicals added to the water
- Generally low maintenance
- Straightforward installation
- Suitable for a range of domestic plumbing applications
- Can help reduce limescale build-up
The effectiveness of magnetic scale inhibitors can vary depending on the specific product, water chemistry and installation conditions, so always follow the manufacturer's recommendations.
How Do Electrolytic Scale Inhibitors Work?
An electrolytic scale inhibitor works using a sacrificial element, typically made from zinc, to influence how scale-forming minerals crystallise as water passes through the device.
The treatment is designed to help reduce the formation and adhesion of limescale within pipework, hot water systems and appliances.
Electrolytic scale inhibitors do not normally require an electrical supply and do not work by chemically softening the water.
Benefits of Electrolytic Scale Inhibitors
- No electrical supply normally required
- No conventional water-softening chemicals
- Suitable for domestic and commercial applications
- Designed to help reduce limescale formation
- Can be used as part of a wider water treatment system
- Available in different sizes and configurations
Because electrolytic units use a sacrificial element, the element may eventually need replacing depending on the product, water conditions and usage. Always check the manufacturer's maintenance recommendations.
Magnetic vs Electrolytic Scale Inhibitors
Both magnetic and electrolytic scale inhibitors are designed to help reduce limescale, but they use different methods.
| Feature | Magnetic Scale Inhibitor | Electrolytic Scale Inhibitor |
|---|---|---|
| Treatment method | Magnetic treatment | Electrolytic treatment using a sacrificial element |
| Electricity required | No | Normally no |
| Chemicals added | No | No conventional water-softening chemicals |
| Maintenance | Generally low | Sacrificial element may require replacement |
| Installation | Typically straightforward | Installed inline within the water system |
| Water softening | No | No |
| Suitability | Depends on product and water conditions | Depends on product and water conditions |
The best option will depend on your installation, water conditions, available space and the manufacturer's recommendations for the particular product.
Scale Inhibitors for Boilers
A boiler scale inhibitor can help reduce limescale formation in systems where hard water is a concern.
Limescale can be particularly problematic where water is heated, as heating can encourage minerals to form deposits. Installing a suitable scale inhibitor may help reduce the build-up of scale within relevant parts of a hot water system.
When choosing a scale inhibitor for a boiler or heating system, always check that the product is suitable for the intended application and follow the manufacturer's installation instructions.
A scale inhibitor should not be confused with a heating system chemical inhibitor, which is used to help protect closed central heating systems from corrosion and sludge. These are different types of water treatment products.
Which Scale Inhibitor Is Best?
There isn't one scale inhibitor that is best for every installation.
The right choice can depend on:
- The hardness of your water
- The type of plumbing or heating system
- Where the device can be installed
- Available pipe space
- Maintenance requirements
- The manufacturer's recommendations
- Whether the application is domestic or commercial
A magnetic scale inhibitor may be suitable if you're looking for a simple, low-maintenance option that requires no electrical supply.
An electrolytic scale inhibitor may be worth considering if you want an inline treatment system that uses a sacrificial element to help control scale formation.
Always check the individual product specifications before choosing a scale inhibitor.
Do Magnetic Scale Inhibitors Really Work?
Magnetic scale inhibitors are designed to help reduce the formation or adhesion of limescale, but their effectiveness can vary depending on the product and installation conditions.
Factors such as water chemistry, flow conditions and the specific design of the device can affect performance.
For this reason, it's important to choose a product from a reputable manufacturer and follow the manufacturer's installation and usage recommendations.
Do Electrolytic Scale Inhibitors Work?
Electrolytic scale inhibitors are designed to reduce the formation and adhesion of limescale by influencing how scale-forming minerals crystallise.
Their performance depends on factors including the specific product, water conditions, flow rate and installation.
As with any water treatment product, check the manufacturer's specifications to make sure the product is suitable for your particular application.
Do Scale Inhibitors Soften Water?
No.
Scale inhibitors do not soften water in the same way as a water softener.
A water softener removes or reduces certain minerals from the water, whereas a scale inhibitor is designed to help reduce the formation or adhesion of limescale while leaving the minerals in the water.
Do Scale Inhibitors Need Replacing?
This depends on the type of scale inhibitor.
Magnetic scale inhibitors are generally low maintenance and do not contain a consumable element.
Electrolytic scale inhibitors use a sacrificial element, such as zinc, which will eventually require replacement depending on the product and usage.
Always check the manufacturer's maintenance instructions for the specific scale inhibitor you are using.
Shop Scale Inhibitors at Plumbco
At Plumbco, we stock a range of magnetic scale inhibitors and electrolytic scale inhibitors for domestic and commercial water treatment applications.
Whether you're looking to reduce limescale in a hard water area, protect a hot water system or find a suitable scale treatment solution for an installation, our range includes options from established plumbing and water treatment manufacturers.
Browse our range of scale inhibitors and find the right solution for your application.
