Two pressure switches?

[Jenny B]

I was looking at a friend’s well pump set up yesterday, they have well water being pumped into a cistern, then connected to a jet pump with a pressure switch— Going through a water softener , two whole house filters and then a UV filter, then into a pressure tank with another control switch, then going to their house. The control switches are wired together. I’ve only been doing plumbing for a couple of years now, so fairly new at this, but I’ve never seen two control switches before— Wouldn’t there only be one? And wouldn’t the pressure tank be placed before all the filters to avoid pressure fluctuations as the sediment builds up? Just curious. They are having some problems with low pressure and having to change the filters more often than normally (I’m guessing they need to clean the tank of sediment and/or add a spin down filter before the other filters). Thanks for your input!

 

[Reach4]

I agree with your thoughts.

I presume the first switch is intended to shut down the pump if the filtering or softener become clogged. Maybe that is a special high-pressure lockoff switch.

 

[Sponsor]

 

[Jenny B]

Hmmm... looked like a really old jet pump- and a regular pressure switch but I could be wrong.

 

[Reach4]

Ahh. Pressure switch built with the pump. It may be turned up high, or may have been bypassed in the wiring.

 

[Jenny B]

Okay gotcha- so the pressure tank control switch would be the primary one... it’s odd though. I would think it could cause problems.

 

[Reach4]

Agreed. A blockage of some sort would deadhead the pump. However, that method would have the advantage of minimizing/eliminating the effects of pressure drops through the stages.

Why does this system need a cistern? Is the well a low producing sand point or something similar?

Do the neighbors have successful well-producing deep wells? Or are the deep wells salty or have some other faults? Some people still run UV with deep wells, but I think they are usually being overly cautious. Better over-cautious than under-cautious.

 

[Jenny B]

Agreed. A blockage of some sort would deadhead the pump. However, that method would have the advantage of minimizing/eliminating the effects of pressure drops through the stages.

Why does this system need a cistern? Is the well a low producing sand point or something similar?

Do the neighbors have successful well-producing deep wells? Or are the deep wells salty or have some other faults? Some people still run UV with deep wells, but I think they are usually being overly cautious. Better over-cautious than under-cautious.

It’s a low producing deep well, with glacial dust? (First time I’ve heard of that too, but there’s tons to learn), and coliform in the water- they’re not sure where it’s coming from. Lots of people here have cisterns and jet pumps and various filter set ups because of issues here with salt intrusion (at low lying areas-it’s an island), coliform, low producing wells etc. It’s a tiny community with only one licensed plumber so I’m trying to get up to speed here so I can help. I’m studying to challenge the test eventually. It’ll take years.

 

[Valveman]

It is fairly common to leave the switch on the side of the jet pump, but wire around it so the switch on the tank is the only one working. You can see the wiring diagram to do that with a jet pump here.

Your pump may also be cycling a lot, which can stir up sediment. And yes filters should be after the tank/switch.

 

[Jenny B]

Thank you! That’s super helpful.