Greetings, Bonnie, and welcome to the forums!
First off is safety. Have you checked the lines to make sure you have no leaks anywhere? Soapy water does a pretty good job.
Assuming no safety issues, what kind of rig is this? A motorhome? A trailer?
If it's a trailer, a really simple way of checking to make sure the problem is not with the tanks is simply to connect one of them (then the other) to a barbeque grill and firing it up. If it fires ok, then the problem is not with the tank.
When you tested at the stove, did you leave the stove on for a minute or so to allow propane to come from the tanks, through the lines, to make it to the stove? With our rig, it always takes about that long after longer storage.
Since you replace the regulator, the problem shouldn't be there.