My furnace was converted to LP gas when originally installed. I was having the furnaced serviced and found the gas pressure on the manifold side of my gas valve to be 3 and 1/2 inches WC. I am told this should be 10-11. There is a tag verifiying the conversion, but how can I ensure that this conversion was properly performed. Would this information be available in the manual? Would you have conversion instructions? I have just recently purchased my home and did not receive any manuals. Any help would be appreciated, Thanks