FAQ

The installer decides what fluid your Alde system is originally filled with.

Preferably Alde-approved antifreeze, which is magenta in colour. We don’t recommend using any non-approved antifreeze products.

About 1 cm above the Min mark when cool. (Then, when the fluid’s heated it will expand up towards the Max mark.)

As a rough guide, touring caravans, B-class and C-class motorhomes hold 10–15 litres, A-class motorhomes and boats hold 20–25 litres.

During service the technician might have left your circulation pump on speed 5 to purge air. Set it back to speed 2–3 for touring caravans and B and C-class motorhomes, or just under speed 4 for A-class motorhomes.

If the heating fluid was changed there may be air in your Alde system. Refer to the operating instructions.

In the UK, they conform to Alde Approval 40X0 2024:

• Alde Protective Premium G12++, G12evo or G13
• Fuchs Fricofin DP
• Comma Xstream G40
• Volkswagen Group G12evo

(Our G13 spec products were discontinued in 2024 so new stock may not be available.)

These products are available ready-mixed with deionised water. Always read the label.

All are intermixable, magenta in colour, providing frost protection to -37 °C and 5 year corrosion protection.

There is a different list of Alde-approved antifreeze products in North America with a completely different chemical base.

Use the same antifreeze product as is currently in the system.

If your heating fluid is magenta in colour, it’s very likely your system is filled with an Alde-approved antifreeze. So top-up with an approved product, they’re all intermixable.

If it is not magenta in colour it is safest to top-up with a cupful or two of deionised water. You will have slightly less protection from frost, corrosion and bacteria, but damage caused by mixing incompatible antifreeze is the bigger risk. Then change the heating fluid as soon as practicable, using an Alde-approved antifreeze product.