Well Pressure Switch Selection

[Art248]

I've just bought my first house, and I'm getting ready to replace the pressure tank. I've purchased a WX-203. I feel like I've got a pretty good handle on the procedure for replacing the tank, what I'm curious about is which pressure switch I should get. Is there a recommended one or is this just preference? Even if it is just preference is there a good method for deciding which one I should go get?

I almost picked up a Square D 20/40 Pumptrol pressure switch when I was at the store, but then I started wondering if that was the right one, or if I should go 30/50 or even 40/60 based on the pre-charge in my tank. The manual just says to adjust the charge in the tank to 2 psi less than the cut in setting on the switch.

I've gotten a lot of useful info from these forums for some of the many projects I've got going on, so I decided to post about it. Hopefully someone can straighten me out. Any and all help is greatly appreciated.

Thanks in advance,

Art

 

[Reach4]

I almost picked up a Square D 20/40 Pumptrol pressure switch when I was at the store, but then I started wondering if that was the right one, or if I should go 30/50 or even 40/60 based on the pre-charge in my tank. The manual just says to adjust the charge in the tank to 2 psi less than the cut in setting on the switch.

2 psi would be for a submersible (down the well) pump, which is what you probably have. Lowering the precharge is easy, and raising it is easy with an air compressor, and may be easy enough with a tire pump -- depending on the pump.

How many stories on your house? If 2 stories plus a basement, you would want 40/60. That would be ok for fewer stories too. 30/50 is good. I had 30/50, and raised that to 38/58 because I could. I don't notice much difference if not watering a lawn.

You can usually adjust a 30/50 up to 40/60, and a 40/60 down to 30/50. Normally you only turn the nut on the big spring, with 3.5 turns being about 10 psi.

 

[Sponsor]

 

[LLigetfa]

I see no details regarding the well and the pump as to whether it could dead head and melt down if you go with too high a pressure. Beyond that, if you were happy with what pressure you had before and the pump did not dead head and die, then go with the same.

 

[S. Hillman]

Art, There is a bit of information lacking from your question. Is it a submersible pump, or a jet pump? Assuming it's a submersible, what horsepower? What depth? How much head? Is your well above, or below your house? How far away? How many floors is your house? Assuming 220v? All things being equal, if you have been happy with your water pressure so far, replace the tank with the same size (20 gal., 30 gal., etc.) The tank pressure must be set to two(2) psi below the actuation pressure of the pump. Example: if your pump kicks ON at 20psi, your tank must be set at 18; 35psi, tank pressure is 33; 40psi, tank pressure is 38; etc. One more thing; that pressure must be measure with the tank EMPTY of water. Once you get a psig reading, shut down the system and drain the tank to get an accurate pressure reading.

 

[Art248]

How many stories on your house? If 2 stories plus a basement, you would want 40/60. That would be ok for fewer stories too. 30/50 is good. I had 30/50, and raised that to 38/58 because I could. I don't notice much difference if not watering a lawn.

House is 3 bedroom, 2 bath. One level plus basement.

 

[Art248]

Art, There is a bit of information lacking from your question. Is it a submersible pump, or a jet pump? Assuming it's a submersible, what horsepower? What depth? How much head? Is your well above, or below your house? How far away? How many floors is your house? Assuming 220v? All things being equal, if you have been happy with your water pressure so far, replace the tank with the same size (20 gal., 30 gal., etc.) The tank pressure must be set to two(2) psi below the actuation pressure of the pump. Example: if your pump kicks ON at 20psi, your tank must be set at 18; 35psi, tank pressure is 33; 40psi, tank pressure is 38; etc. One more thing; that pressure must be measure with the tank EMPTY of water. Once you get a psig reading, shut down the system and drain the tank to get an accurate pressure reading.

I have no information on the pump at this time. I believe it to be a submersible pump. I'm getting about 15 gpm from it. The well is below my house. Probably 20 feet or so. House is 1 floor at ground level plus a basement. 3 bedroom, 2 bath. 1000 sq. ft. I believe it's 220. I got the house with known issues. Has had variable water pressure, but regularly fairly low. I believe due to bad bladder in pressure tank. A neighbor does water/wells for work and recommended I size up to the 32 gallon.

 

[Reach4]

You could have gone bigger. 32 gallon is the biggest with 1 inch NTP connections, next comes 1-1/4. Rule of thumb is that you want the pump to pump a minute or more each time. Another approximation is that your 32 gallon tank will hold 32/4 =8 gallons So at 8 gpm, you would fill the pressure tank in about a minuter.

30/50 or 40/60 psi would be fine for you. If torn, adjust to 35/55.

 

[LLigetfa]

Has had variable water pressure, but regularly fairly low. I believe due to bad bladder in pressure tank.

Unless the bad tank was overheating the pump causing it to thermal trip, the blame is not the tank. The tank does not provide the pressure, the pump does. Even with a bad bladder, the pump pressure should vary between the cut-in and cut-out setting on the switch.

 

[LLigetfa]

30/50 or 40/60 psi would be fine for you. If torn, adjust to 35/55.

You cannot know that unless you have inside knowledge of the pump's dead head pressure. Seeing as the OP gets 15 GPM, it may be sized for volume rather than pressure.

 

[Reach4]

You cannot know that unless you have inside knowledge of the pump's dead head pressure. Seeing as the OP gets 15 GPM, it may be sized for volume rather than pressure.

Possible but unlikely IMO.

S. Hillman, if you put in 40/60, make sure the pressure was climbing pretty well at the end. If it was running out of steam, choose a lower pressure.

 

[Art248]

You could have gone bigger. 32 gallon is the biggest with 1 inch NTP connections, next comes 1-1/4. Rule of thumb is that you want the pump to pump a minute or more each time. Another approximation is that your 32 gallon tank will hold 32/4 =8 gallons So at 8 gpm, you would fill the pressure tank in about a minuter.

30/50 or 40/60 psi would be fine for you. If torn, adjust to 35/55.

Okay, just to make sure I understand, I can go with either 30/50 or 40/60, depending on whether I would like a little more or a little less pressure?
So this is a preference kind of thing, or was the information I gave about the house the determining factor?

 

[Art248]

Unless the bad tank was overheating the pump causing it to thermal trip, the blame is not the tank. The tank does not provide the pressure, the pump does. Even with a bad bladder, the pump pressure should vary between the cut-in and cut-out setting on the switch.

The pressure goes up until the cut-out, then rapidly drops. I was told by my neighbor this could be due to a hole in the bladder of the pressure tank. Pump seems to run frequently when using minimal amounts of water.

 

[LLigetfa]

The pressure goes up until the cut-out, then rapidly drops. I was told by my neighbor this could be due to a hole in the bladder of the pressure tank. Pump seems to run frequently when using minimal amounts of water.

The pump starting and stopping frequently is a symptom of a waterlogged tank but again, the pressure you see is the same you would see with a good tank only the time between the highs and the lows would be longer.

You really need to know what the dead head pressure is on your well/pump. Keep in mind if the well draws down, so too does the dead head pressure. You could get away with jacking up the pressure for a while only to have it melt down later if the water table drops.

 

[LLigetfa]

By not posting this in the Pumps and Tanks forum, you might be missing some very good advice from folks that do this for a living.

Here is one sample thread that talks of the peril of a pump dead heading.
https://terrylove.com/forums/index.php?threads/check-valve-bad-burnt-up-well-motor.86836/

 

[Reach4]

The pressure goes up until the cut-out, then rapidly drops. I was told by my neighbor this could be due to a hole in the bladder of the pressure tank. Pump seems to run frequently when using minimal amounts of water.

Could be a leak, due to a number of things. Leak in the pitless gasket. Leak in the drop pipe, above or below water. Leak in the pipe between the house and the pitless. Bad check valve at the pump.

One simple thing to do is to close the valve that shuts off water to the rest of the house, and see if this cycling continues.

Some leaks you could see or hear by lifting the well cap. A bright flashlight at night or a mirror reflecting the sun by day can light the top part of the casing.

Describe "rapidly drops". When the cycling occurs, and you are not using water, how many seconds is the pump on, and how many seconds is the pressure dropping?

A workaround to the various leaks is to add a check valve before the pressure pump. It is best to not have one of those usually. But if pulling the pump and checking and fixing, that can be useful to give you some time.

It would be best to get that fixed soon.

 

[Valveman]

A 32 gallon tank only holds 8 gallons of water. Your pressure will be low and variable even with a 40/60 switch as it will go from 40 to 60 and 60 to 40 for every 8 gallons used. Here is a video to help you understand what a pressure tank does and how to get better pressure.

 

[Art248]

By not posting this in the Pumps and Tanks forum, you might be missing some very good advice from folks that do this for a living.

Here is one sample thread that talks of the peril of a pump dead heading.
https://terrylove.com/forums/index.php?threads/check-valve-bad-burnt-up-well-motor.86836/

Is there a way to move this thread to the appropriate forum?

 

[Art248]

Could be a leak, due to a number of things. Leak in the pitless gasket. Leak in the drop pipe, above or below water. Leak in the pipe between the house and the pitless. Bad check valve at the pump.

One simple thing to do is to close the valve that shuts off water to the rest of the house, and see if this cycling continues.

Pump does not appear to cycle when using no water.

 

[Art248]

The pump starting and stopping frequently is a symptom of a waterlogged tank but again, the pressure you see is the same you would see with a good tank only the time between the highs and the lows would be longer.

You really need to know what the dead head pressure is on your well/pump. Keep in mind if the well draws down, so too does the dead head pressure. You could get away with jacking up the pressure for a while only to have it melt down later if the water table drops.

So you're saying it would be a safer bet to go with the 20/40 switch that I had originally looked at?

I'm still trying to understand what factors are in play here and how to choose the "correct" pressure switch.

 

[Art248]

A 32 gallon tank only holds 8 gallons of water. Your pressure will be low and variable even with a 40/60 switch as it will go from 40 to 60 and 60 to 40 for every 8 gallons used. Here is a video to help you understand what a pressure tank does and how to get better pressure.

The video seems to say that the 32 gallon tank I've already purchased will be fine if I added a CSV to my system. How spendy is something like that, and how difficult are they to install?