62. Microfilter: This small polyester felt sock, which fits over the motor bottom willrequire periodic inspection. Dust will discolor the microfilter. Change the microfilteras soon as any discoloration is easily noticeable. Do not shake this microfilter sincethis can cause liberation of potentially harmful microscopic dust into the air.Carefully remove and discard with collected debris in the sealable poly bag. Ifequipped with a Gore-Tex microfilter, the same rules for periodic inspection anddisposal apply. The Gore-Tex microfilter, which features a clamp that holds it inplace, must be changed when any abrasions, damage or heavy discoloration is noticedon the surface of the filter (refer to photo 1).3. HEPA or ULPA Exhaust Filter: This cartridge is mounted onthe top of the motor, outside the container. If the main filterand microfilter are properly maintained, the glass fiberelement in the exhaust filter should perform satisfactorily for aminimum of one year. It cannot be renewed or restored. Exactlife will depend upon frequency of use and amount and typeof material collected. Normally four changes of microfilterequal one change of HEPA/ULPA filters. Remove theprotective metal casing and replace the pleated glass fibercartridge according to the accompanying instructions (photo8). Cartridges must be replaced more frequently if the vacuumcleaner has had unusually heavy use, or if the various pre-filters have been neglected.CAUTION: Use only genuine Nilfisk replacement filter components. The use ofsubstitute components could pose a grave risk of personal exposure, and will cause allequipment warranties to be void.TROUBLESHOOTINGLoss of Power:1. Make sure the power cord is properly fastened to the motor head, and it’s properlyplugged into the socket.2. Be sure the electrical circuit has not blown a fuse.3. If the circuit is functioning properly, but there is still no power, contact the NilfiskCustomer Service Department at (800) 645-3475, extension 2.Loss of Suction:If the GM 80 loses suction power during operation, there may be several reasons,the most likely of which is a full container. Suction loss is gradual as the container fillswith debris. Check to see if there is any blockage or restriction in the hose.1) Check the condition of the main filter and microfilter (refer to photos) and determinewhether there is an excessive loading of debris. If there is overloading in the mainfilter, you can shake it out. If the problem exists with the microfilter, including if it isloaded, it needs to be replaced. Call our Customer Service Department at (800) 645-3475, extension 2 to order a replacement.2) If all fails, call our Customer Service Department at (800) 645-3475, extension 2.Photo 8