My propane gas grill won't get hot, any way to fix it?

All I can say is that it seems to not put out much in the
way of a flame.

I turned it all the way up to high.

It's a used grill. Seemed to work better the first 2 times
I used it, but now the flames seem very low.

Since all 3 burners don't put out much, it seems
to be the regulator?

Somebody posted about possible spider webs in BBQ grills?

Another said you have to disconnect and reconnect a propane tank
because the regulator sometimes hangs up.
I've switched tanks and have the same problem, so it must be
the regulator??