Setting Well Pressure

[Valveman]

Short cycling is rapid on/off/on/off. It DOES NOT HAPPEN with a normal system with normal precharge. Running sprinklers will not wear out a pump. In that system, drawing a small amount of water will cause the pump to run only if it is very near cut-in pressure already.

Of course if one were to run 5 or 6 sprinklers at the same time they might start to approach 'short cycling'

If what you believe were true every household in the country would be replacing pumps every few weeks.

According to the motor manufacturers, rapid cycling is usually anything less than 1 minute on and 1 minute off. But they also have a limit of 100 or 300 cycles per day, depending on the size of the pump. A 2HP pump is in the 100 cycles per day list, so that would be no more than about 4 cycles per hour. And that is just to make sure it makes it through the warranty period, not to make it last 20-30 years. I was floored when I found out all pumps are built with planned obsolescence as the major design factor.

Every household in the country is replacing the pump every 7 years on average, because that is how many cycles is built into each pump. Some may last 30 years, but others only last months or even weeks, mostly depending on how they cycle. I think that average maybe even shorter now, as so many pumps are being DIYed. I was told 7 years by pump manufacturers 20-30 years ago.

Whether or not 5-6 sprinklers will cause the pump to cycle, depends on how many sprinklers the pump can supply. If the pump is only large enough to supply 6 sprinklers, then running 6 sprinklers will keep the pump running continuously, which is what they like to do. But if you run any less than 6 sprinklers, the extra water produced by the pump fills the tank and causes the pump to shut off and then continue to cycle on and off. How fast it cycles then depends on how large the tank is. The larger the tank, the slower the cycling, but the longer the pressure swings from low to high, usually 40 to 60.

 

[Valveman]

Questiabout the cycle stop: I knew they existed but have never run into a system using them...yet. Does that not cause the pump to come on when one draws a glass of water? Been meaning to dig into it on google but too lazy.

A CSV will work with any size tank. And the tank size determines how many glasses of water you can draw before the pump starts. It will come on faster with a smaller tank, so in the old days you would want as large a tank as you could get through the door. However, even large tanks do not keep a pump from cycling when using water for longer terms like showers and sprinklers. As was discussed earlier, if you have a tank large enough to make the pump stay on for 1 minute and off for 1 minute, that is 30 cycles per hour when running fewer sprinklers than the pump is made for.

A CSV would keep the pump running continuously no matter if you are using 1,2,3,4,5, or 6 sprinklers, and/or when the shower is on. The water just goes right past the tank to the sprinklers or shower, so the size of the tank is a moot point. Only when you flush a toilet or use a small amount of water will the tank even be used.

The idea of the small 4.5 gallon size tank that only holds 1.2 gallons of water, is that if the CSV eliminates 30 cycles per hour for long term uses like showers and sprinklers, adding back 30 cycles per day for toilet flushes and hand washing still won't cause as many cycles as the old big tank method. Using the CSV with a larger tank kind of gives you the best of both worlds. But the larger tank does keep you from seeing the strong constant pressure for a longer time, and we have found over 25 years that the cycles saved are not worth the added expense and space needed for a larger tank.

 

[ns_in_tex]

If your pump is cycling with the sprinkler system running, maybe, you could just increase the sprinkler orifice size just enough that the pump could not reach cut off pressure. This would stop cycling and keep good pressure for all other appliances.

We installed a 15 year old pump which was given to us, 8 years ago. The electrical run to the pump is 1,465'. The first storage tank & pump controls are 635' from the pump. It has already lasted longer than we expected. Not sure, but suspect the quality of water may have something to do with it.

 

[Valveman]

If your pump is cycling with the sprinkler system running, maybe, you could just increase the sprinkler orifice size just enough that the pump could not reach cut off pressure. This would stop cycling and keep good pressure for all other appliances.

We installed a 15 year old pump which was given to us, 8 years ago. The electrical run to the pump is 1,465'. The first storage tank & pump controls are 635' from the pump. It has already lasted longer than we expected. Not sure, but suspect the quality of water may have something to do with it.

Opening up more sprinklers to use as much water as the pump can produce use to be the only way to keep a pump from cycling when irrigating. But it is hard to make every sprinkler zone the same size and to use enough to keep the pump from cycling. Plus when your sprinklers have the pump maxed out, you have no pressure left for house use. So you have to run sprinklers only during times when the house will not be using water like 2-6 AM.

With a CSV you can match the sprinklers to the yard and not the pump. You can still use a large zone in the back yard. But you can also use a medium size zone in the side yard and a little bubbler zone in the driveway without causing the pump to cycle. Even the largest zone can be 3-5 GPM less than the pump can supply, so you can run sprinklers anytime of day and not starve the house for pressure. Also all the different size zones will run at a constant pressure. That way they can be adjusted to hit the corners exactly every time they go around.

Like I said, depending on how they are used, some pumps will last a long time. But the general method of failure is that they cycle on/off as planned according to the size of the tank until the bladder/diaphragm breaks from bending back and forth. Then the tank is waterlogged and causes the pump to cycle even faster (really rapid cycle) until the pump/motor itself is destroyed and needs to be replaced.

Diaphragms in the tanks and the pumps themselves are designed to survive 5-7 years of average cycling. When you start losing air in the tank and the cycling rate increases, the life of the pump/motor is close at hand.

 

[Xfaxman]

I added a pressure gauge to the input of the hot water heater so I could see that everything was copacetic from inside the house:

View attachment 535214

Why do you want to know the inlet water pressure for your hot water tank?
Would you suspect it to be different than your cold water pressure throughout the building, or are you just trying to confirm what your overall house pressure is?
If you turn on any faucet, and the flow is weak, you will know that you have a pressure problem.
I can't see that reading the house inlet pressure is going to give you much useful pump/tank information.

The gauge is on the other end of the line from the tank at the well, that is outside a long way away. It shows me the pressure in the pressure tank and that everything is working right. If the pressure slowly drops when we aren't using water, there is a problem, like a leaking toilet flapper, fill valve or outside hydrant.

I also have a light at the well, that can be seen from the house, it comes on when the pump runs.

Yesterday I checked the pressure gauge a few minutes after the pump had shut off. It was 4 pounds lower than normal. I watched the gauge and could see the pointer moving down very slowly.

I went out to the well, turned off the valves to the house and to the barn. The gauge on the pressure switch held steady, meaning the anti-drain back valve in the well was good. Turned on the valve to the house, still good, meaning no leaks in the house. Turned on the valve to the barn and the pointer started moving down very slowly. It was 18 degrees out there and the horse water tank was full, so I turned off the valve and went back into the warm house.

 

[turnkey4099]

According to the motor manufacturers, rapid cycling is usually anything less than 1 minute on and 1 minute off. But they also have a limit of 100 or 300 cycles per day, depending on the size of the pump. A 2HP pump is in the 100 cycles per day list, so that would be no more than about 4 cycles per hour. And that is just to make sure it makes it through the warranty period, not to make it last 20-30 years. I was floored when I found out all pumps are built with planned obsolescence as the major design factor.

Every household in the country is replacing the pump every 7 years on average, because that is how many cycles is built into each pump. Some may last 30 years, but others only last months or even weeks, mostly depending on how they cycle. I think that average maybe even shorter now, as so many pumps are being DIYed. I was told 7 years by pump manufacturers 20-30 years ago.

Whether or not 5-6 sprinklers will cause the pump to cycle, depends on how many sprinklers the pump can supply. If the pump is only large enough to supply 6 sprinklers, then running 6 sprinklers will keep the pump running continuously, which is what they like to do. But if you run any less than 6 sprinklers, the extra water produced by the pump fills the tank and causes the pump to shut off and then continue to cycle on and off. How fast it cycles then depends on how large the tank is. The larger the tank, the slower the cycling, but the longer the pressure swings from low to high, usually 40 to 60.

I question that 7 year figure. My pump should have been replaced twice already according to that. It is istill going strong. The community well one Running thee small acreages was old when I moved in and went another almost 20 before it was replaced. In fact I have worked on zero wells, all pressure tank ones and never had to replace a pump. I haven't even heard of any neighbors replacing them.

 

[turnkey4099]

A CSV will work with any size tank. And the tank size determines how many glasses of water you can draw before the pump starts. It will come on faster with a smaller tank, so in the old days you would want as large a tank as you could get through the door. However, even large tanks do not keep a pump from cycling when using water for longer terms like showers and sprinklers. As was discussed earlier, if you have a tank large enough to make the pump stay on for 1 minute and off for 1 minute, that is 30 cycles per hour when running fewer sprinklers than the pump is made for.

A CSV would keep the pump running continuously no matter if you are using 1,2,3,4,5, or 6 sprinklers, and/or when the shower is on. The water just goes right past the tank to the sprinklers or shower, so the size of the tank is a moot point. Only when you flush a toilet or use a small amount of water will the tank even be used.

The idea of the small 4.5 gallon size tank that only holds 1.2 gallons of water, is that if the CSV eliminates 30 cycles per hour for long term uses like showers and sprinklers, adding back 30 cycles per day for toilet flushes and hand washing still won't cause as many cycles as the old big tank method. Using the CSV with a larger tank kind of gives you the best of both worlds. But the larger tank does keep you from seeing the strong constant pressure for a longer time, and we have found over 25 years that the cycles saved are not worth the added expense and space needed for a larger tank.

Thanks, so the CSV does not cause the pump to run every time a faucet is opened. The pressure tank, no matter how small is sort of a buffer?

 

[turnkey4099]

If your pump is cycling with the sprinkler system running, maybe, you could just increase the sprinkler orifice size just enough that the pump could not reach cut off pressure. This would stop cycling and keep good pressure for all other appliances.

We installed a 15 year old pump which was given to us, 8 years ago. The electrical run to the pump is 1,465'. The first storage tank & pump controls are 635' from the pump. It has already lasted longer than we expected. Not sure, but suspect the quality of water may have something to do with it.

I like that - real shade tree mechanic thinking. I can't see any reason it wouldn't work excpet all the fidling around getting it right. Installing a CSV would probably be easier. I don't know what the cost but it shouldn't be much over a standard switch.

 

[buickanddeere]

To reduce the number of start-stop cycles I set the pressure band as wide as the switch would allow and still function reliably. Starts at about 20psi and shuts off at 55psi. The low end pressure is noticeable while in the shower or watering the flowerbeds.

 

[Valveman]

To reduce the number of start-stop cycles I set the pressure band as wide as the switch would allow and still function reliably. Starts at about 20psi and shuts off at 55psi. The low end pressure is noticeable while in the shower or watering the flowerbeds.

I see that a lot and it is a certain clue that cycling is a problem. Not only is the low pressure noticeable in the shower and sprinklers, but you are over-stretching the diaphragm in the tank, which greatly shortens its life. Plus the fact that you notice the low pressure in the shower and sprinklers means the pump is still cycling.

In the last 50 years I have sold dozens of different brands of pumps. That 7 year average life was told to me by several of those manufacturers. For every pump that last 30 years, there is another that didn't last 30 days.

At one time I was replacing close to 2000 pumps a year. One year I made note of the date codes as I was loading the old pumps to haul off for scrap metal. Out of 2000 pumps of all makes and sizes, the 7 year average was almost perfect.