I assume from your question that you own the tank. With that assumption- is the tank within it's test date? On the neck of the tank is the date of manufacture, or subsequent test dates. The original manufactured date is good for 12 years, the test date is good for 5 years. I would suggest that you take the tank to a propane supplier for repair. If in fact the tank is out of date, it may be worth your while to just purchase another tank, as the cost of the tank repair & testing may be more than a new tank- I'd price it both ways before making a decision.