Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: I have gone through 5+ of these

I have gone through 5+ of these over the past 2 years. For some reason, they work as long as they are not unhooked. Once you unhook them, they seem to rarely work again. There is something about the propane tank fitting that will no longer pass gas. I have read that some of them simply corrode shut.Not a good value.