If your butane torch is not filling up, there are a few potential reasons why. The first possibility is that the valve on the butane canister is not open all the way. If this is the case, simply open the valve fully and try again. If the problem persists, it could be that the nozzle on the torch is clogged. Try cleaning out the nozzle with a needle or paper clip. Finally, if neither of these solutions work, it's possible that your butane canister is empty and needs to be replaced.