gas pipe size

Any plumbers want to comment on the gas piping that was installed by my hvac guys to install a tankless water heater? I have a few concerns. And yes I should have inspected their work more thoroughly before they left. To start it looks like I have at least a 1 inch pipe running to my meter...

Good evening, I am respectfully requesting assistance in the sizing of a gas line for a pool heater. My local inspector will allow me to install the line on my own and once I get a licensed gas fitter to connect to the mainline, they would inspect everything. – hence the question to the experts...