It is advised that you keep your grease extraction system cleaned on a regular basis to keep it in a good clean working manner, we also install access doors (inspection hatches) free of charge you only pay for the access door/hatch only.
here are the required cleaning periods :-
If your kitchen is working -
2 - 6 hours per day = once a year.
6 .- 12 hours per day = every 6 months
12 hours or more per day = every 3 months