Well pump pressure switch

[sdyver]

I'm having some problems with the pressure switch on my irrigation well pump. I live in Florida and I have a 1hp pump on a shallow well (50ft). Everything has been working just fine until I went away for a week and noticed the yard was dry when I returned. I ran through the zones and the pump wouldn't turn on. I had the person that installed the well/pump come and check it out and he said it worked fine, but at the time I had power secured to it so he ran it off a generator. This past weekend we went away and the check valve coming from the well broke, and I replaced it. When I applied power to the pump, the pump came on and one of the irrigation zones was on, but the pump would cycle. The pressure switch was turning the pump off at about 35-40 psi. I adjusted and lubricated (WD-40) the pressure switch today and ran all my zones without problem and the pump shut off by itself. When I went out to check it a few hours after the last zone ran, the pressure read 0 psi. I can manually trip the relay on the pressure switch and the pump will pressurize to 55-60 psi. For some reason the pressure switch won't kick the pump on. Any idea what could be causing this? Could it be a problem with the sensing line going from the pump to the pressure switch? Any help appreciated. Thanks.

Mark

[rogersdawn2]

if the line to the switch gets clogged with dirt or sediment it will make the pump very erratic

[Eric in North TX]

And they aren't expensive enough to lose sleep over, try another. That is something every well owner should have one as a spare anyhow. They do wear out.

[Harry K]

Yep.

1. Pull the 'line' (1/8" riser pipe) to the pressure switch and see if it is plugged, if so clean it.
2. If the pipe riser is clear, replace the pressure switch. They only cost a few lattes

Harry K

[gfretwell]

I am on a 2 pump system (aireator) and I got tired of screwing with these things in the middle of the night. (do they ever break any other time) My pump switch is on a quick disconnect (hose type) with a plug and receptacle pigtailled off of it. You can "hot wire" the plug from the pump right to the power in an emergency or you can swap out the pump switch in less than a minute. I keep a known good spare in the pump house so my wife can even do it.

[desperado]

They do get old, and do wear out, but also temperature can play havoc at times. I had a case where the temperature here in the Mojave desert got over 100 degrees and caused the pressure in the pressure tank to rise due to the air heating up in there. It is usually set 2 psi below cutin. If the switch started to cut in when the temp was high, it cycled, sometimes to the point of tripping the breaker due to high starting current making the average current draw larger than usual. I solved the problem by installing a gate valve in the pipe inlet to the switch, and barely cracking the valve open. This created a dampening effect kind of like a shock absorber and worked well for me. Always have a gage attached to the pressure switch line; it will help you diagnose many problems quickly.

[Harry K]

I suspect something else was going on. The pump would only try to start at the low pressure (cut-in) setting, not the high (cut out) setting.

I don't think an air temp of 100 degrees is going to raise the pressure in a tank more than a pound or two.

Harry K

[John Gilmer]

If the ground water temp was 55 or so, then the "air soak" would raise temp by 45F. On an "absolute" scale, that's about 10%. IOW: it could be as much as 3 or 4 lbs.

[nicksanspam]

How do you figure that?

Nick