Rain Barrel pump and pressure switch

[themp]

I have the following cheapo pump and good pressure switch with a foot valve on a 300 gallon rain barrel. A hose is connected to the pump to water plants and such.

http://www.lowes.com/pd_67599-296-FS...la&cagpspn=pla

http://www.northerntool.com/shop/too...duct_7738_7738

The pressure switch works find when the hose is cycled for watering for about ten minutes and then the pressure switch fails to work anymore. If I let things 'cool' down or wait for period of time then it all starts working again. I did one test where I just turned on the hose for about 5 minutes and then when the hose was turned off the pump continued to run. So, it is tied to how long the pump operated. I do not see any leak in the system. I am guessing maybe the foot valve is leaking but that is hard to get at as it is at the bottom of the tank. Or some kind of air is getting into the system. Water discharge from the hose does not change when it starts failing. I took the top off the pressure switch and all looks well, no rusting or bugs, etc.

Any ideas on what is happening here? Thanks, Tom

[Porky]

You have a 30-50 pressure switch and a centrifugal pump. Most centrifugal pumps can't build enough pressure to turn off your pump. If you want an automatic on-off system you should have a jet pump. However you may try backing off the long screw in the pressure switch until the pump shuts off! What size tank do you have on the system? You will need at least a one gallon bladder tank otherwise the pump will continue to cycle!

[themp]

Interesting, when I built this thing about 3 years ago during the drought I just have the pump, pressure switch and a hose connected to the output of the pump. Until this summer it worked fine, meaning when you turn off the hose the pump would build up enough pressure in the hose to cause the pressure switch to turn off. No bladder on this. And if I leave power to the pump on it will not come on again until I turn the hose on, so the system stays pressurized. It is just after a period of time of using the pump that the switch starts failing to cut off the pump. Let it sit for a while with power turned off to the pump and it starts working again after turning power back on. I get really good output from the hose, meaning it is just like it was connected to the city water supply.