Well pump cycling

[Zaffer]

I just installed a new well and new everything associated with a new well. I am clearing the well after finally getting everything up and running. I’ve read it is ideal to run the water for at least 24 hours continuously to clear sediment and chlorine. I did shock my well when I installed the pump.

The water is pretty clear, especially when looking at it through a glass, but I’ll continue to run the well.

I have the valve turned so it’s running at about 4 gpm; my well refresh (as calculated by the well drillers) is 6 gpm. Well is 523 feet deep, but I set the pump at 300 feet with static level at about 60 feet. My well pump currently turns on every 3-1/2 minutes to refill my 86 gallon pressure tank.

My questions are these: Should I adjust the flow rate or is keeping it where it is okay? Am I doing any damage to my well pump?

This is new territory for me.

Thanks!

 

[RetiredInGueydan]

It is best to run the pump continuously and not cycle on/off to prevent unnecessary wear. Just monitor the water flow so it doesn't pump down and allow the pump to get air.

 

[Sponsor]

 

[Zaffer]

That’s what I’m trying to manage. The pump still shuts on and off with the valve all of the way open. I sized the pump with the well engineer.

 

[RetiredInGueydan]

How large of pump and how small of valve is being used? Open more piping for discharge.

 

[Zaffer]

1.5 hp pump and standard boiler valve at the pressure tank. I can’t open anything else as I need to keep the system in the house separate from the well so the water doesn’t mix, per the town. Right now I have a ball valve shut off to prevent this from happening.

 

[RetiredInGueydan]

Where is the pressure tank located? This should have been done before connecting to the house system.

 

[Zaffer]

Not sure what you mean concerning the pressure tank. It’s 12 feet from the well head in my basement. I have a 1” line going to my main water line with an inline ball valve between the two.

 

[RetiredInGueydan]

I would pull the drop pipe off of the pitless adapter and flow open pipe. If not you may be doing more harm than good.

 

[Zaffer]

By this do you mean that I should have the water drop back into the well, essentially in a circulation mode? If so, how does this clear the well?

 

[RetiredInGueydan]

Discharge to the ground with a full pipe.

 

[Zaffer]

Gotcha.

 

[Valveman]

You have a pump that wants to put out about 3 faucets worth of water. Using anything less than 3 faucets wide open will cause the pump to cycle on/off no matter how large the pressure tank. A larger tank just slows the cycling down. But there are 1440 minutes in a day, so a cycle every 4 minutes is 360 cycles per day. 100 cycles a day is too many for a pump that size.

Adding a Cycle Stop Valve will let you use as little as 1 GPM without the pump cycling. The CSV will work with the large tank you have, but would have been fine with just a 5 gallon size tank.

 

[Reach4]

I have the valve turned so it’s running at about 4 gpm; my well refresh (as calculated by the well drillers) is 6 gpm. Well is 523 feet deep, but I set the pump at 300 feet with static level at about 60 feet. My well pump currently turns on every 3-1/2 minutes to refill my 86 gallon pressure tank.

What is your pump? The reason I ask is based on that, there might be a PSI target before your throttling valve that would represent a pressure where the water has fallen to maybe 250 ft. Not sure that is going to work, but pressure plus GPM could probably do that even better.

For developing the well to clear sediment, higher flow is better.

 

[Valveman]

Higher flow is usually better for developing a well like Reach says. But it is hard to develop a well when the pump is cycling, at any flow rate. While you are using a 4 GPM faucet, the pump is pumping 12 GPM for 3.5 minutes, then 0 GPM for 5 minutes. This is causing the well to be surged up and down, making it hard to develop. You may need to pump high volume and pull the water level down to better develop the well, but not on a time limit of how much water a 86 gallon tank can store. Some wells develop better running a lower flow for longer periods of time. However you get the well developed, it will always produce less sediment if the pump is not cycling when using water for normal house uses. Many sandy wells stop producing sand when a CSV is added as the water level is no longer being continually surged up and down.

 

[Zaffer]

With the valve fully open, it’s producing about 9–10 gpm. I ran it this way for about an hour as that let the water level drop and keep the pump on without cycling. I turned it off as we were going to bed and I didn’t want the water level to possibly drop below the pump and burn the pump up. When I shut it off, I “checked” the water level and it had dropped to around 200 feet, so I was still about 100 feet above the pump. I had the valve open to about 4 gpm as I didn’t want to drop the water level, but then the well pump cycling was a concern as well. I ran it wide open today for a couple of hours and it dropped to about 100 feet, with the pump barely cycling.

I purchased the pump and install kit from RPS, but I’m wondering if the pump is oversized. I stated that I MIGHT drop the pump to 400 feet in the future if 300 wasn’t enough, so maybe it was sized based on that info? Either way, the water is full running clear, even from the start, and there is no smell of chlorine. I’m going to have the water tested before we open the valve to the house and see how it comes back. I’ve run the well for about 9 hours total so far, so I’ll see where that gets me, though I plan to run it more tomorrow. I’ve read running it constantly is the best for clearing, but it’s clear right now.

 

[Valveman]

I purchased the pump and install kit from RPS, but I’m wondering if the pump is oversized.

All pumps are oversized. You have to install a pump that can handle peak demands, but the majority of the time the system is using a fraction of that amount. You also set the pump at 300'-400' because you don't know how far the water level will draw down when using peak demands. But when using average flow, which is a fraction of what the pump can do, the water level will not draw down. Even though the pump is set at 300'-400', it is only lifting from the actual water level, which in this case is 60'. Now you have a pump designed to put out 10 GPM from 400' plus 50 PSI (115') for the house pressure that is only lifting from 60' and delivering water to a 3 GPM shower. The pump is way oversized 90% of the time. But when you have a large demand of 3 showers+ going at the same time and the water level draws way down, the pump is no longer oversized.

In the old days we would use as large a pressure tank as possible and just let the pump cycle on and off for 90% of the time it is being used. However, cycling destroys or causes problems with everything in a pump system. The pressure switch points will be the first thing you notice getting burned. The capacitor and start relay in the control box are usually the next things to go. By this time you will start hearing the water hammer when the pump starts and stops as the check valve(s) are failing from slamming when the pump cycles. The sediment stirred up in the well being surged from the pump cycling on and off makes check valves fail as well. Soon the diaphragm in the tank will tear from bending back and forth with every pump cycle and the tank will be water logged. Next you will notice the lights flickering and the pressure surging as the pump is rapid cycling every time you crack open a faucet. While standing in the shower with soap in your hair the water will just suddenly stop. But wait, in just a minute or so the water magically comes back on. This is because the overload in the motor is auto-resets after it cools down for a minute or so. You should probably go ahead and replace the pump at this point, or you can just wait for the overload to not reset after it does this a few more times.

The point is, all the problems you are having and all the problems you are going to have can be avoided by simply eliminating pump cycling. Solving all those problems and making pumps and systems last several times longer than planned by the manufacturers is why the Cycle Stop Valve is considered a disruptive product in the pump industry. With such a deep set pump working at only 60' and low flow you will need to check the back pressure. More than 200 PSI would need extra consideration. But that would be the only thing to check when adding a CSV1A to solve all those problems and deliver strong constant pressure to the showers at the same time.

Find the max head of the pump and subtract 60' for the back pressure when using a CSV.

 

[Zaffer]

I appreciate the feedback. At the moment I’m not having any issues, that I know of anyway. I’ll look into the CSV and gather more info on it. I’ll take a look at the above info as well. I know the engineer asked about all of that and calculated everything I gave him to wind up at the size pump I now have.