Still catching up on the house maintenance and I know I have to check the bladder pressure on the well tank as we have a few issues with water pressure in the house. So I did what any sane individual(?) would do and educate myself on YouTube...
Most of the videos by actual plumbers or plumbing supply companies mention that the pressure switch for the well pump tends to default to 40psi/60psi for on/off pressures. Ours is set to much lower pressures (IIRC it switches off in the mid-high thirties and on in the mid-high twenties). I'm mostly trying to understand why, especially as the tank is in the basement of a two story + basement house.
I can't quite remember how deep the well is but it's not that shallow (for some reason 80' comes to mind, but it feels like that's too much - I'll have to verify this in the house paperwork) and it's quite far from the house (probably 75-100') so I'm wondering if the system is run that way to put less load on the well pump, or because the plumbing in the house can't take higher pressures. Obviously I don't want to find out the latter the hard way.
Any pointers?
Around 50 is pretty normal. Less than that and water pressure on the second floor is going to suck. Distance isn't going to cause much additional load on the pump. Head is what loads the pump, as in how high is it lifting the water. Any modern well pump should handle 100' plus without issue. Some of them will pump closer to 500' of head.
As you get closer to the head limit of the pump, water pressure and volume will fall off. They may have set the pressure that low because the pump wouldn't reach 50-60 psi.
If your well does not produce, or if it is old and partially plugged with sand or rust, the pump pressures need to be set lower so it does not cavitate. Sometimes they can be cleaned to get some performance back but if it was a crappy well to begin with your stuck unless you try again.
Cleaning involves dropping a blasting cap down the hole in my area which is fun.
If you have a drilled well with a submersible they can run higher pressures than a sandpoint with a suction type jet pump, provided the water volume is there.
Thanks. The water volume should be there as the well was producing around 40g/minute when it was drilled in 2003. We also didn’t notice the pump struggling to refill the pressure tank (although I never specifically tested that).
I guess it might be worth having the well checked by a professional if I can find one and see if they have any suggestions.
If I’ll actually manage to get off my shop roof (trying to fix some leaks) I’ll see if I can figure out what the actual pressures at the tank are.
In reply to BoxheadTim :
You don't need a pro if you want to play with it yourself. Bypass the pressure tank and switch and run the pump at full flow for an hour. Measure the gpm and seee if it draws down. If it does you can use a pressure washer hose with a jetter end and drop it down to blow all the crud loose and test it again.
https://www.google.com/amp/s/www.cleanwaterstore.com/blog/well-pump-flow-rate/amp/
Ultimately it depends on what your pump can produce. Typically you use a 40/60 pressure switch on a submersible deep well pump. Typically use a 30/50 on a shallow well jet pump. If water table is high you can crank up pressure a bit. If pump is worn you can turn down pressure a little. You want to avoid making the pump struggle to hit the high limit to shut off. If the needle of the gauge gets near cut off and just keeps bouncing for a minute or so, then the switch is set too high. If it hits limit quickly and shuts off, then turn pressure up. You never want a pump to run for less than 45 seconds at a time. Long runs are ok. Short cycles like when the bladder is compromised will burn a pump out.
Thanks for all the info. Turns out the pump was set to turn off at about 45 psi and turn back on at 25. Unfortunately the pressure bladder was also sitting at 25psi...
Anyway, I flushed the tank a couple of times - the first couple of times, the water from about 25psi down to zero psi came out completely black with sediment (or whatever that was - the system has an air injector upstream of the well tank, so it could've been corroded "stuff" as well). I flushed it a few more times until it came out light gray, probably have to go back and do it again. Oddly enough the water comes out clear most of the time until the well tank is almost empty. It's only the last 2-3 gallons that have a lot of sediment in it.
I also upped the working pressure a little bit - apparently the switch for the pump is set to 30/50 by default. The pressure gauge shows a little "jitter" in the pressure reading between about 45psi and 48psi, but the pressure seems to go up steady during that time with only minimal jitter/bounce of the needle. The fill rate of the tank does appear to slow above 45psi so I didn't want to set the cut-off pressure even higher. Right now the switch is set to 28/48 with the bladder pressurised to 26psi.
One other odd thing I noticed is that when I was flushing the tank, I could get about 20 gallons of water out of the tank, maybe 22-23. Given that we've got a 52 gal well tank, this seems a bit less than I was expecting. Obviously there has to be space for the bladder so I wasn't expecting the full 53g, but I was surprised I wouldn't even get 30. Is this normal?
