It's actually pretty simple

Alde-approved antifreeze

We research and test antifreeze products in-depth and over the long-term, to provide you an approval list you can trust 100%.

Please note that in North America there is a different list of Alde-approved antifreeze products with a completely different chemical base.

What does the antifreeze do?

The heating fluid transfers heat from the Alde boiler, around the pipework to the heat emitters. It must be comprised of an Alde-approved antifreeze product. Why, what else does it do?

Protects against frost damage, down to -37 °C.
Protects against corrosion damage for 5 years.
Prevents bacterial growth.
Prevents boiling, cavitation and foaming, reducing noise.
Lubricates the circulation pump.

It’s the lifeblood of the heating system so it’s crucial that it’s the right stuff.

Approval Process

There’s more to being an Alde-approved antifreeze product than specification on a label. It must be:

Lobrid formula intermixable with all Alde-approved antifreeze products.
Available ready-mixed 50:50 with deionised water.
Magenta in colour.
Manufacturing facility passes Alde audit, including verification of certificates and QA batch sampling.
Pass 2-year real-time, real world wet test.

Only then do we award Alde Approval 40X0 2024.

What to top-up with

Alde-approved antifreeze products are available as concentrate or ready-mixed. (Concentrate should be mixed 50:50 with deionised water.)

You should only top-up with Alde-approved antifreeze products if the heating system is filled with the same.

Some installers use their own, non-approved products and provide support for them. If so, they’ll be able to advise you what to top-up with.

If in doubt, you can top-up with a cupful or two of deionised water and protection won’t be seriously impacted. Then, change the heating fluid as soon as practicable using an Alde-approved antifreeze product.