Help! Pump does not kick in unless I drain water in the system.

[Mfm020]

Hello everyone.
I have a seasonal camp on a high hill overlooking a lake. The pump draws water from a lake, and pumps it up the hill to the camp. There is a pressure tank in the camp, and one at the pump. Both are at 28 psi. I have a new 30-50 switch on the pump. Pressure is good, pump stops properly at 50 on the nose.

Th problem is that the pump will not automatically turn on. I have to drain all the water from the house by opening the lowest faucet - then it comes on. I suspect this is because the weight of the water in the long downhill run between house and pump keeps the pressure at the switch just above 30. When i remove the water by draining the house, the pressure lowers and the pump kicks in, pumps until 50 and shuts off.

I was thinking that switching out the 30-50 for a 40-60 might do the trick. Am I on the right track?

Thanks for your suggestions!

[Cary Austin]

Just tighten the large adjustment nut three turns to the right and you will turn the 30/50 switch to 40/60.

[Mfm020]

Thank you Cary. Three turns did the trick.

[Mfm020]

Hi again,
So, cranking up the cut in pressure by adjusting the large nut worked. It is now coming on at 34 and my pressure tanks (in house and at pump) are both at 32. The problem is adjusting the large nut also cranked up the cut out level to the point where the pump cannot seem to reach the cut out pressure. I've tried backing off the small adjusting nut to the point where there is barely any pressure on the spring. It doesn't seem to want to go lower than the 20 pound differential set by the large nut. I'd like to set it be 34-50 - but can't get below 54.

Any thoughts?

(By the way, pump shop told me it could do 60 psi last time it was in for a repair. Was thinking that the uphill run was giving it grief...)

[Cary Austin]

A regular pressure switch just will not let you adjust to less than about 20 PSI differential.  Sometimes backing all the way off on the little screw will give you like 17 PSI between on and off, but not always.  There are other pressure switches that will do less than 20 PSI Delta but they are not cheap.  I have an electronic pressure switch that will do as little as 10 PSI differential.  You can find it at this link.

https://cyclestopvalves.com/products/electronic-pressure-switch-1