Boiler cleaning product

When should it be used ?
Use at the beginning of the heating season and then every two months, taking account of the quality of the fuel, the importance and the duration of the heating period.

INSTRUCTIONS FOR USE

Mix 1 litre of product with 5 litres of water.
Turn the boiler off.
Spray abundantly by the door or by the inspection traps of the walls and flues of the boiler (any garden spray can be used, then rinse after use).
Turn the boiler back on at a minimum of 60°C, for half an hour.
Turn it off again and to remove the burnt residues from the bottom of the boiler.