I could not unscrewed the burned out light bulbs from my Vent-a-hood. One bulb burned out first, a few months later, the other one went too. Glen came and he had to open up the hood with a special tool to replace the bulbs. He packed everything up into his van and ready to go. We chatted for a bit and he asked me when did I clean the wheels inside the blower. I said I cleaned the box around the wheels regularly but I never clean the wheels in 17 years because I could not get the wheels off. When he heard that, he unpack his tools, came back in, open up the blower box, took the wheels off with another special tool, showed me the grease and dirt accumulated inside the wheels. It was quite disgusting. We degreased one wheel with dishwasher soap, and replaced the other with a new one. Now, my hood function much better. He also gave me a tip to always turn both blowers on when cooking , leave it on 10 mins before and after cooking to ensure all smoke and grease are clear out. The two wheels spin in opposite direction and they work together efficiently to remove smoke and grease. I never knew that. Thanks Glen for your excellent service and advice. You are the best. Namaste.