my buddy has an older central boiler he is looking to sell he bought it used from a guy and wasn't in operation since. he gave 800.00 for it and said I can have it for what he paid. Anything I should look for on the unit that would mean its not good anymore?. He said the guy he got it from filled it with water and it didn't leak but never had a fire in it. Is this a good deal or let it where its at and forget about it. Thanks Brad