i'm no pool expert - we are slogging thru a pool remodel. i was told that the behavior you describe is what i would experience if i didn't upgrade my gas line. i had the power company out and the put in a bigger meter. i would also have a plumber check to see if you have some kind of auto shut off feature (here in CA -we have "earthquake valves") if the valve isn't sized right for the draw - i think you could have that kind of experience too. but really i'm no expert