well jet pump
Posted by Sam on February 20, 2004 at 09:30:38:
My pump still pumps water; but it no longer shuts off. When I turn it on the pressure gauge creeps up to 40#, then just stays there and will not go any higher nor kick off. In the past, it kicked on at 40# and kicked off at 60#. Since it ran a long time without rest before I discovered this, I thought that maybe the impeller was damaged from heat. So I replaced the impeller but my problem remained. I fiddled around a little with the screws on the pressure switch, but did not really know what I was doing. Any idea on a) what my problem is and b) how to get the pressure switch readjusted to the proper position?

My pump is a Craftsman Shallow Well Jet Pump (� HP; 40/60 pressure; Model # 390-251882). It sits atop a Sears Captive Air Water Tank. The whole thing sits atop my well. The foot valve is about ten feet below the pump; but lately the well has been full to the top, which means the water level is only a couple of feet below the pump. I don�t know whether the switch is a �D� . The rectangular black plastic cover which fits over the switch does not contain a model number, but says: Type: SK-2 Model: STA-RITE Part Number But then there is no number. The switch contains four raised screws in a straight line which hold wires; and there are three lower adjustment screws: #1 is in the middle, with #�s 2 and 3 on either side. Instructions in the cover say: �Device Adjustment: 1) Turn nut #1 CW to raise cut on & off pressure 2) Turn nut #2 to raise cut off pressure only�
I do not understand these instructions. (I did not install this system, although I have replaced a few parts through the years). Furthermore, I do not know why the switch would be out of adjustment, anyway. I have never had to adjust it before (I was just fiddling with it lately out of desperation).

Let me recap this: my water pipes into the house froze, then unthawed---although I don�t think the pump froze. Now my problem is that the pump goes up to 40# pressure, then just keeps running without shutting off. I replaced the impeller and re-plumbed several fittings which were leaking. I now have only a slight dribble where the hose from the tank attaches to the pump outlet. This (lack of leaks) is better than it has been in years. Since this problem developed I have kept the power to the pump shut off except when I am running water in my house. But even when it is shut off overnight, the system seems to hold its prime, but not the system pressure. The pump just won�t shut off.

I tried draining (power off) the tank of all water, and checked the air pressure is. The AIR pressure in the tank should be 2 lbs below the pump cut-in pressure. The air pressure in the tank was 6# (so where did that pressure go? Do I have a leak? It seems to have been fine for several years now, but water in the tank may have frozen at the beginning of this problem�). So I inflated the air pressure to 38# and it seems to be holding there: I checked it after an hour and it had not budged. But when I primed and restarted the pump, the gauge quickly raised up to 28# and would not go any higher. And now, it seems, my system does not even hold that pressure (up until now it had held this low pressure overnight).

About five minutes after I shut off power to the pump, the pressure gauge on the tank (not the air pressure) had gone back down to almost nothing.
What do you suggest next? Do I make some adjustment on the pressure switch? I still do not understand the instructions for adjusting it. Thanks for your patience�
---sam



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