3/4" pipe used with natural gas, is good for 200,000 btu's for a 14 foot run... but for every 90 degree L or tee, you have to add 5 feet of pipe to the get an equivalent length for sizing the pipe. for instance if you have 5 such fittings you have an equivalent length of 34 feet, thats good for 117,000 btu's of *input.
is rated at 199,000 BTU. so input, the 3.4" pipe is generally considered grossly insufficient for the typical gas company pressure regulator settings....the pipe run needs to be 1"'
That said, there is a 50/50 chance that too small gas piping is not the problem... depending on the gas pressure at the utility company meter... if
it is a propane
rated unit and you are running propane, 3/4" gas pipe at an equivalent length of 34 feet is OK.
I need to know how many fittings are between the gas meter and the water heater
That said, generally the pressure at a test plug in the burner manifold is 3.5" water column, but I need to confirm that for this model. It may take me a while tomorrow to find the manual on that unit.
meantime let me know how many fittings are in that gas line.