The problem you're having requires disassembly of the machine and checking three areas: the bag safety switch, the secondary safety switch, and the pressure valve. You will need to have it repaired by someone with knowledge of these vacs. There are ways to work around the interlock switches, but it would involve changing some wiring, which is not recommended. If you need any more help, our email is arctic@worldlynx.net
Help Around the House, December 2006