Hi Glen, thank you for your response. The heater does not have a perssure guage, but I do own one already.
When I test the line for leaks I used the air value like fitting to pump pressure into the line and it did not leak.
I needed to verify the pressure from the gas input. So tonight I...
I am exprienced DIY, but I have new project to install a tankless water heater. The mfg requires the pressure in the gas line to be with 4. to 10.5 w.c. (aprox 1/8 to 1/2 PSI). What is the procedure for testing the gas w.c.? I know I need to disconnect the tankless water heater to do this...