A: A dirty filter means that the extractor fan has to be run at a higher setting to achieve the expected results and this increases the energy consumption and noise. Therefore the grease filter in a cooker hood must be regularly cleaned – about once a month.
Some cooker hoods have disposable, changeable filters which are easy to just throw away and replace. If your cooker hood is equipped with metal filters or aluminium filters just soak in hot soapy water in the sink for 20 minutes. For the main part of the cooker hood you can try a citrus degreaser or Cillit bang degreaser (green topped bottle) Spray it onto a cloth then scrub clean using a sponge or soft cloth (be careful not to use anything abrasive).