A DIY'er installed a 1.5 hp pump to feed three drip zones, each drip zone is approx. 450ft with a 1gph emitter every 12''. The whole system is run with half inch lines except for a 1.5in intake. The intake is about 80 feet with a check valve and no pressure reducer. Well, the pump will run a zone for about two minutes and then the thermal shutoff will turn the pump off (so the pump is getting hotter than 120 degrees). I tried hooking a garden house to the top of the pump and the thermal shutoff still turned it off after a couple minutes. Does anyone have any idea what the problem might be?? Anything I should try/check??