Hayward H400 install question

I currently have a Hayward H400 which is >10yrs old and is being replaced by the new model H400. All the connections(water, gas, electric) seem to be in the same position so it should be an easy swap ( I hope). In the manual it states that all new installations should have the gas line and pressure tested upon hookup. Since my old heater worked fine is this really necessary, or can I assume that the line pressures are okay since they were previously and the gas supply and meter have not changed? Of course I will leak test all the fittings before fire-up.

No one with any experience?

Answering this question can involve a lot of liability. You need to do or not do the installation based on your interpretation of the manual or have a pro do it for you based on his/her experience.

I'd say..........check every connection with soapy water with everything open and the heater not running. This will give you an idea if you have any leaks.
Normally, messing around with 10 year old screw fittings, something will need
to be tightened up. The soap and water at each joint and valve will tell you
after you replumb the new unit.

Checking the gas pressure at the gas valve inlet and outlet is a piece of cake if you have the W.C. gauge....

That's part of the problem. I don't have the gauge. But since the old heater was installed professionally and was working properly, can I assume that the gas pressure is acceptable?

With mine, when I installed it, it would not light. The gas co. had to increase my meter pressure and flow, by replacing the meter itself.
Since you already had a heater, you should be OK. I did not.