Radiator Flushing Chemicals

Chemicals used in radiator flushing

Maintaining a central heating system is completed not only with a machine, but also with the right chemicals. Cleaning chemicals dissolve limescale, sludge, and corrosion deposits that accumulate in radiators and pipes. Protective chemicals guard the cleaned system against new corrosion. Antifreeze products prevent freezing in systems that are unused in winter or run through outdoor areas. The category also includes leak sealers for closing minor leaks and pH test strips.

Which product is used and when?

• Radiator flushing chemical: Used together with a radiator flushing machine to dissolve deposits.
• System protection chemical: Added to the system after flushing and rinsing; slows down corrosion and deposit build-up.
• Antifreeze and corrosion inhibitor: Used in systems at risk of freezing and in solar energy circuits.
• Leak sealer: Helps close minor leaks in the system.
• Litmus (pH) test strip: To verify whether rinsing has been completed.

Correct use

Each chemical must be used at the ratio specified by the manufacturer and in proportion to the water volume of the system. If the system contains aluminum radiators or special materials, check that the chemical is compatible with those materials. Do not leave the cleaning chemical in the system longer than the recommended time; rinse thoroughly with water after the process. Do not mix different chemicals; follow the sequence: clean, rinse, then protect.

Safety

When working with chemicals, wear gloves and eye protection, and read the safety information on the packaging. Store chemicals in a cool, dry place out of reach of children. Dispose of waste cleaning water in accordance with local regulations.

Frequently asked questions

Is a protective chemical necessary?

Adding a protector after flushing helps the system stay clean for longer.

Does a leak sealer close every leak?

It can be effective on minor leaks; visible cracks and breaks require mechanical repair.

Can antifreeze be used in a combi boiler system?

Only products and dosages approved by the combi boiler manufacturer should be used.

How is a pH test strip used?

Dip the strip into a water sample taken from the system and compare the resulting color with the scale on the packaging.

How much chemical is needed?

The amount depends on the water volume of the system; it is calculated according to the ratios on the product label.

How long should the chemical be left in the system?

The dwell time is stated in the product's instructions for use. Exceeding the recommended time provides no additional benefit and may, on the contrary, cause undesirable effects on sensitive materials.