Problems with a Grundfos booster pump. (first-time post)

Users who are viewing this thread

Tyler Fowler

New Member
Messages
2
Reaction score
0
Points
1
Location
Massachusetts
Hello all,

After quickly looking through some post hear, I get the sense that Groundfos pumps are not very reliable. I looked for a post that would help me out, but none I found answered my questions.

My father-in-law has a Grundfos MQ pump in the basement of his two story home to increase the water pressure in the system. It is installed right after the water meter in the basement. The pump will not turn itself on. If I manually turn the pump off, then back on, the pump starts and runs for 10-15 seconds. I checked the faucet while turning it off and on, and the pressure does increase for the 10-15 seconds.

After that the pump turns off and does not turn back on, no matter how many faucets are open.

I was reading the install manual and it mentions the two things that should turn the pump on;
"The MQ is equipped with both an internal flow switch and pressure switch.
Each of these can turn the MQ on, depending on water
consumption. The pump will start when:
The flow rate is greater than 0.3 gpm
OR the pressure is below 29 psi."

I cannot find any pressure gauge so I thought maybe the water pressure from the town is already at or above 29 psi?​

I'd like to try to fix the pump, it's only a couple years old. But, if the pump is junk, maybe I can install a better system. I saw "Pside-Kick kit with a CSV" listed in another post that seemed like it would work for the house.

This is my first time dealing with a booster pump so let me know if ya'll need any extra info I may have overlooked/left out.
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
Yeah if the city pressure is 30 PSI, the pressure in the house is miserably low, but it is enough to keep the MQ from coming on. Flow switches are not a reliable way to start a pump as you can see. But is could also just be a bad circuit board, which is also very common on those pumps.

It is never good to have a pump that cannot be adjusted to the pressure you need it to work. A Pside-Kick kit with a CSV and a regular mechanical 40/60 pressure switch on a standard jet pump is pretty fool proof.
 

Tyler Fowler

New Member
Messages
2
Reaction score
0
Points
1
Location
Massachusetts
Yeah if the city pressure is 30 PSI, the pressure in the house is miserably low, but it is enough to keep the MQ from coming on. Flow switches are not a reliable way to start a pump as you can see. But is could also just be a bad circuit board, which is also very common on those pumps.

It is never good to have a pump that cannot be adjusted to the pressure you need it to work. A Pside-Kick kit with a CSV and a regular mechanical 40/60 pressure switch on a standard jet pump is pretty fool proof.

I'll speak with my father-in-law and see what he wants to do. Not sure if he installed the Grundfos or had it installed. Thanks for the quick reply!
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
Pressure gauges are cheap and readily available. Some have a garden hose thread, so one of those could screw to your laundry tub, water heater, or a hose valve.
 

GRANT MANHART

New Member
Messages
1
Reaction score
0
Points
1
Location
South Dakota
They're about a 3 yr unit under the best of conditions
I had to replace grundfos pump on artesian well water heat pump after 2 yrs. Bearings shot. Assumed it was dirt in water so put in 40 gal holding tank to allow sediment to drop.... New pump short cycling after 2 yrs....pressure sensor shot or pipe blockage in the heat pump screwing up pressure and flow....your observation of 3 yr pump life cycle is pretty accurate to this point...plus I need a licensed plumber account to get one locally from our supplier.... plus 700 bucks every two years is not what I would call economical....Seriously, Grundfos?
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
All pumps are made to sell and have a short time fail date built in. Makes more money for the manufacturers. It is up to you to figure out that reducing or eliminating on/off cycling is the only way to make pumps last longer. Most people learn the hard way that variable speed controllers and electronic controllers with flow switches are not the way to make pumps last longer.
 

The Daggs

New Member
Messages
1
Reaction score
0
Points
1
Location
Colorado
All pumps are made to sell and have a short time fail date built in. Makes more money for the manufacturers. It is up to you to figure out that reducing or eliminating on/off cycling is the only way to make pumps last longer. Most people learn the hard way that variable speed controllers and electronic controllers with flow switches are not the way to make pumps last longer.[/QUOT
Yeah if the city pressure is 30 PSI, the pressure in the house is miserably low, but it is enough to keep the MQ from coming on. Flow switches are not a reliable way to start a pump as you can see. But is could also just be a bad circuit board, which is also very common on those pumps.

It is never good to have a pump that cannot be adjusted to the pressure you need it to work. A Pside-Kick kit with a CSV and a regular mechanical 40/60 pressure switch on a standard jet pump is pretty fool proof.


We moved into a brand new 15 home cul d sac and the houses have been here 3 yrs So far 3 homes with the pumps has had theirs leaked including us. We live atop a hill and find the pressure lower but doable without it. I don't think I'll spend another $500 for another 3 yrs of faster hair rinses

]
I had to replace grundfos pump on artesian well water heat pump after 2 yrs. Bearings shot. Assumed it was dirt in water so put in 40 gal holding tank to allow sediment to drop.... New pump short cycling after 2 yrs....pressure sensor shot or pipe blockage in the heat pump screwing up pressure and flow....your observation of 3 yr pump life cycle is pretty accurate to this point...plus I need a licensed plumber account to get one locally from our supplier.... plus 700 bucks every two years is not what I would call economical....Seriously, Grundfos?
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
We moved into a brand new 15 home cul d sac and the houses have been here 3 yrs So far 3 homes with the pumps has had theirs leaked including us. We live atop a hill and find the pressure lower but doable without it. I don't think I'll spend another $500 for another 3 yrs of faster hair rinses

You are lucky you have some pressure without the booster. But I hate that you don't have strong constant pressure in the house, as that will rinse your hair even faster. A standard jet pump, which can produce constant pressure by using a CSV, can last 20-30 years.

You probably won't be surprised to find out that Grundfos stopped making the MQ. Now they make a new variable speed all plastic pump called the Scala or something like that. My first impression is that the Scala is going to be worse than the MQ. Of course that is worse for the homeowner, but better for Grundfos, as they will get to sell you a new one every year or two.
 

Elvis Chu

New Member
Messages
1
Reaction score
0
Points
1
Location
Taiwan
Hi,

I really suggest you to have a try the SSA series of Stairs pumps, nomatter your incoming pressure exceed your pressure setting or what, you dont need to adjust any setting, and this pump is silent and full protect function installed.



Hello all,

After quickly looking through some post hear, I get the sense that Groundfos pumps are not very reliable. I looked for a post that would help me out, but none I found answered my questions.

My father-in-law has a Grundfos MQ pump in the basement of his two story home to increase the water pressure in the system. It is installed right after the water meter in the basement. The pump will not turn itself on. If I manually turn the pump off, then back on, the pump starts and runs for 10-15 seconds. I checked the faucet while turning it off and on, and the pressure does increase for the 10-15 seconds.

After that the pump turns off and does not turn back on, no matter how many faucets are open.

I was reading the install manual and it mentions the two things that should turn the pump on;
"The MQ is equipped with both an internal flow switch and pressure switch.
Each of these can turn the MQ on, depending on water
consumption. The pump will start when:
The flow rate is greater than 0.3 gpm
OR the pressure is below 29 psi."

I cannot find any pressure gauge so I thought maybe the water pressure from the town is already at or above 29 psi?​

I'd like to try to fix the pump, it's only a couple years old. But, if the pump is junk, maybe I can install a better system. I saw "Pside-Kick kit with a CSV" listed in another post that seemed like it would work for the house.

This is my first time dealing with a booster pump so let me know if ya'll need any extra info I may have overlooked/left out.
 

phil Tuttobene

New Member
Messages
7
Reaction score
0
Points
1
Location
Orlando, FL
Website
www.totalautomationworks.com
Hi,

I really suggest you to have a try the SSA series of Stairs pumps, no matter your incoming pressure exceed your pressure setting or what, you dont need to adjust any setting, and this pump is silent and full protect function installed.

Another fairly unknown residential/light commercial booster pump that is growing popularity due to its robust design and 3 year warranty is Perfect Pressure Pump. .

This pump does not require a flow sensor and detects water flowing using complex algorithms. I like that because there is no pin wheel to get plugged up or caked up with calcium or water born mineral deposits over time. Their exclusive predictive PID algorithm allows the pump to respond very fast to demand changes without hunting, over or undershooting the set point.

It does not have any plastic. Plastic that will crack and fall apart when exposed to sunlight. This pump is more of an industrial design, good looking, quite, totally wash down, comes with a sun shield at no extra cost & features powder coated aluminum and stainless steel construction. It's easily adjustable with a simple pressure knob from 0 -75PSI output. No keypad to fade over time or go bad.

Hope you find a reliable pump, this is my choice.

All the best,
Phil
 
Last edited:

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
Hi Phil. I wish you all the best. I watched the videos and looked at the specs. While it does have some good features, I don't see it any different than a couple dozen other VFD type booster systems already on the market. I remember the Hays Pump from the mid 90's. It was one of the first residential size VFD's systems on the market. They had "predictive PID algorithms" and all that stuff as well. The most recent one I have seen is the Scala, which replaced the Grundfos MQ discussed previously in this thread. Every few months electronic technology gets better and they think the new "algorithms" will solve all the previous problems. So every 18 months or so there is a new version (Generation 11 or something) hits the market. And every 18 months or so the last generation is no longer available. In the 25 years or so I have been keeping up with it I think Generation 11 or 12 is about right.

Here are my observations on the perfect pump. Very few VFD systems use a flow switch anymore. They all use a pressure transducer like the one attached above the check valve. And I know they say "tankless", but a little tank would give the VFD some time to react. That way you wouldn't see the pressure gauge dip from 80 to 60 PSI as fast, like it does in the video, which by the way is not really constant pressure. There is only one size pump, and one size does not fit all I am afraid. It will only boost incoming pressure, not lift from a well, or draw from a cistern. Not mixing the air sounds like a cool way to keep bugs and lint out of the electronics, but it will still need to be kept in a fairly cool environment. In a little enclosed space or sitting out in the desert sun I think it will overheat like all VFD's do. And it says it will do 22 GPM at 40 PSI using a 2HP VFD on a 1.5 HP motor. A good 1HP regular jet pump will pump more water than that.

But like I said, I wish you the best. I'm all for it. It does show that a big pressure tank is no longer needed and teaches how important constant pressure can be to the pressure in the house. And once you've gone constant pressure you will never go back to the old big pressure tank type system.
 

phil Tuttobene

New Member
Messages
7
Reaction score
0
Points
1
Location
Orlando, FL
Website
www.totalautomationworks.com
Hi Phil. I wish you all the best. I watched the videos and looked at the specs. While it does have some good features, I don't see it any different than a couple dozen other VFD type booster systems already on the market. I remember the Hays Pump from the mid 90's. It was one of the first residential size VFD's systems on the market. They had "predictive PID algorithms" and all that stuff as well. The most recent one I have seen is the Scala, which replaced the Grundfos MQ discussed previously in this thread. Every few months electronic technology gets better and they think the new "algorithms" will solve all the previous problems. So every 18 months or so there is a new version (Generation 11 or something) hits the market. And every 18 months or so the last generation is no longer available. In the 25 years or so I have been keeping up with it I think Generation 11 or 12 is about right.

Here are my observations on the perfect pump. Very few VFD systems use a flow switch anymore. They all use a pressure transducer like the one attached above the check valve. And I know they say "tankless", but a little tank would give the VFD some time to react. That way you wouldn't see the pressure gauge dip from 80 to 60 PSI as fast, like it does in the video, which by the way is not really constant pressure. There is only one size pump, and one size does not fit all I am afraid. It will only boost incoming pressure, not lift from a well, or draw from a cistern. Not mixing the air sounds like a cool way to keep bugs and lint out of the electronics, but it will still need to be kept in a fairly cool environment. In a little enclosed space or sitting out in the desert sun I think it will overheat like all VFD's do. And it says it will do 22 GPM at 40 PSI using a 2HP VFD on a 1.5 HP motor. A good 1HP regular jet pump will pump more water than that.

But like I said, I wish you the best. I'm all for it. It does show that a big pressure tank is no longer needed and teaches how important constant pressure can be to the pressure in the house. And once you've gone constant pressure you will never go back to the old big pressure tank type system.
Thank you for your comments, I will try to address some of them here:

1) The pump comes in TWO sizes, not one. up to 31 GPM, 2 hp. It will cover 95% of all residences. We also have a 3 and 5 hp in development and later a duplex for condos.

2) Many VFD systems DO use a flow switch. The Scalia 2 is a good example. Other industrial boosters, I can name a dozen, use inferior low /no flow algorithms. Some use motor current or motor frequency to determine when there is no flow. Both of these methods do NOT work reliably because the point a pump stops flowing changes with the suction so either the pump will continue to run in certain suction scenarios burning the pump out or it will cycle on/off excessively effecting system life and performance.
Other companies simply look at pump temperature and turn off the pump when it gets too hot. Kind of like having a smoke detector for a current limit control.

3) No one has our predictive PID algorithms, Which a much lower performance version of it won the ASPE innovations award in Chicago in 2011. Ours are advanced and are used in the most prestigious high rise buildings in the world. We have been developing this algorithm for the past ten years so we know it works and works well. Lower performance versions of it are actually being used in hundreds of high rise buildings around the world. One such building was 106 stories, the building engineer would pre-charge the system over a period of 5 minutes going from 50 PSI to 475 PSI. Our algorithm did it in 15 seconds with only 3 PSI overshoot! People are still talking about that. Plus when the pressure is at set-point, no longer do pipes jingle, jangle, jingle on the hangers. Pipes are perfectly still because there is NO hunting like most other "predictive PID" algorithms.

4) Our response is 1 second from suction pressure of 40 PSI to discharge of 75 PSI (capped at that). Why do you care if the pressure takes 1 second to reach pressure? Everyone knows when you get in a shower or turn on a faucet, 1 second response is nothing. Plus you get the added advantage of ramping and controlling the pressure, prolonging the fixtures. The small deviation you get for example in the video was with a toilet AND two sinks additionally running. Look at the suction in the video, it's at 20 PSI! We did this intentionally to show we actually do what we spec. 42 PSI boost at 22 GPM. That's the SMALL unit. If you set the pressure to 60 PSI vs 75 PSI you would have much less deviation. 55-60 PSI is typically all you need.

5) We do NOT need a flow switch, unlike most of our competitors, we developed a no flow algorithm that knows when to turn the pump off without the high maintenance flow sensor which usually is a pin wheel that spins. This pinwheel always ends up getting clogged with minerals, Teflon tape, pipe dope, etc. This algorithm is SO accurate it can detect flows down to 1/4 GPM.

6) The drive unlike most competitors is 100% powder coated aluminum. Meaning the entire VFD is a heat sink. We have an internal fan that moves air around when needed but even in Florida, we never have seen this fan operate, especially when we use our Sun shield.

7) We have no plastic. Plastic will always crack in sun light. ALWAYS. We have no digital keypad. Keypads and membranes will always fail in Sunlight. Always.

5) Our all stainless steel check valve is external and easily taken apart to be cleaned. Check valves are the highest maintenance items behind bladder tanks and then pump seals. We give the customer the ability to take it off, take it apart, clean the seal and reinstall. A 20 minute job instead of most competitors needing to have the entire pump taken apart.

6) Our pump seal can be replaced in less than 10 minutes. and there are only two. Unlike multistage pumps that have several and are very hard to replace.

7) Our algorithm allows the pump to leak down to suction when demand is not needed. Saving energy from all competitors that keep the pressure high and cycle. This is the REAL reason they use bladder tanks, to lower the pump cycling while the system leaks down, and they all leak down over time. Our system keeps the pump off for weeks or even months at a time if on vacation for example, who cares what the house pressure is when there is no demand?

You are correct about pulling from a well or cistern, the pump needs positive suction but we intended it to boost a wells pump, not replace it.

All the best to you sir. Sounds like you have a good grasp on boosters. Great conversations!
 

phil Tuttobene

New Member
Messages
7
Reaction score
0
Points
1
Location
Orlando, FL
Website
www.totalautomationworks.com
All pumps are made to sell and have a short time fail date built in. Makes more money for the manufacturers. It is up to you to figure out that reducing or eliminating on/off cycling is the only way to make pumps last longer. Most people learn the hard way that variable speed controllers and electronic controllers with flow switches are not the way to make pumps last longer.

There are two ideologies out there. Build them cheap to last 1 year so more profits can be made in service or build them right to last years.

Look at the materials. Plastic right off is a sign of cheap...cheap...cheap!!!!

Second look at the warranty. 1 year is a sign that the manufacturer is sweating for 12 months hoping their product will last long enough to charge you for over inflated, proprietary parts. Think that $800.00 VFD controlled pump saved you money? Well if you have to replace it every 1-3 years, think again.

That mentality almost destroyed American car manufacturers. I remember purchasing a 1998 Caravan and having to take it in every month for something. Traded it in for a Honda Accord, the one time I brought it in (had 130,000 miles) all the mechanics were reading the newspaper with no cars in the bays. I always buy Honda's due to that one experience.

Running a motor on a VFD is an art. Having designed VFDs over the past 38 years, I know what to look out for. EMF, Ground noise, Eddy Currents that destroy motor bearings, low carrier frequencies and high carrier frequencies that both have their own traps. Running a motor below its rated curve and how that damages pumps.

Having the right motor windings rated at the right DV/DT and having them wound properly to prevent pin hole phase to phase faults due to PWM waveforms.

Running a motor on a VFD WILL, if done RIGHT extend the life of the motor. Typical MTBF is 22 years when done CORRECTLY. But many pump companies are NOT VFD experts. They know little to NOTHING about VFDs, they are pump people, they understand pump curves, affinity laws and the such but they are NOT electrical engineers that have specialized in VFDs since their inception in 1976.

I constantly am hired to consult to large munis around the world, educating them how to optimize their applications using VFDs, regardless of manufacturer. Even the manufacturers fall short setting their defaults.
 
Last edited:

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
I couldn't agree more. You are saying the same things I was saying back in 88-93 when I was working with VFD's. I kept saying we know how to insulate wires to prevent corona damage. We know how to filter dirty power. We know how to ground rotors to prevent eddy currents from destroying bearings, and on and on. And over the years they have gotten much better at these things.

Most importantly as you said, pump guys don't understand VFD's and Drive guys don't understand pumps. When you start with a background in pumps like I did, you figure out that the old centrifugal impeller pump is hard to improve upon. Many of the qualities people try to build into their VFD's are already a natural characteristic of the centrifugal pump. A centrifugal impeller will pump a lot of water or very little, it will use less energy when restricted to a lower flow, and more energy when opened up, without varying the speed of the pump. I like to say a VFD is just trying to trick a pump into doing something it already does naturally. Power consumption or amp draw will reduce by restricting a full speed pump with a valve the same way the amps drop when reducing the speed with a VFD. But most people don't know that. They think the pump has to be slowed down with a VFD to reduce energy consumption, which is not true.

All you need is a valve that can control and deliver constant pressure to the house. The backpressure from the valve will make a centrifugal pump work at high flow and high amperage, or low flow and low amperage. This gives the same performance to the house or water system as a VFD, without having to deal with any of the problems with VFD's that you mentioned.

I think 22 years is quite a stretch, because like you said "running a motor with a VFD is an art". You have to make sure everything is right, and there are very few people who know how to do that. You are saying the same things I have been hearing for decades. I thought for years that someone would figure out how to solve those problems. But I finally decided there is nothing that can be done to change the laws of physics, so the VFD will never beat the natural characteristic of the centrifugal pump.
 

phil Tuttobene

New Member
Messages
7
Reaction score
0
Points
1
Location
Orlando, FL
Website
www.totalautomationworks.com
I couldn't agree more. You are saying the same things I was saying back in 88-93 when I was working with VFD's. I kept saying we know how to insulate wires to prevent corona damage. We know how to filter dirty power. We know how to ground rotors to prevent eddy currents from destroying bearings, and on and on. And over the years they have gotten much better at these things.

Most importantly as you said, pump guys don't understand VFD's and Drive guys don't understand pumps. When you start with a background in pumps like I did, you figure out that the old centrifugal impeller pump is hard to improve upon. Many of the qualities people try to build into their VFD's are already a natural characteristic of the centrifugal pump. A centrifugal impeller will pump a lot of water or very little, it will use less energy when restricted to a lower flow, and more energy when opened up, without varying the speed of the pump. I like to say a VFD is just trying to trick a pump into doing something it already does naturally. Power consumption or amp draw will reduce by restricting a full speed pump with a valve the same way the amps drop when reducing the speed with a VFD. But most people don't know that. They think the pump has to be slowed down with a VFD to reduce energy consumption, which is not true.

All you need is a valve that can control and deliver constant pressure to the house. The backpressure from the valve will make a centrifugal pump work at high flow and high amperage, or low flow and low amperage. This gives the same performance to the house or water system as a VFD, without having to deal with any of the problems with VFD's that you mentioned.

I think 22 years is quite a stretch, because like you said "running a motor with a VFD is an art". You have to make sure everything is right, and there are very few people who know how to do that. You are saying the same things I have been hearing for decades. I thought for years that someone would figure out how to solve those problems. But I finally decided there is nothing that can be done to change the laws of physics, so the VFD will never beat the natural characteristic of the centrifugal pump.

Thank you for your opinion, unfortunately tests prove valving alone is not as efficient as slowing down the pump. Federal mandates are now requiring VFDs on all commercial boosters over 10 HP. Of course this does not apply to houses, yet.

I love your product BTW, Cycle stop valves has its place so I understand your bias against varying the pump speed.
My well pump is 350 ft from the house and I need a booster at the house to maintain good pressure. Your valve will not boost pressure. I also have a 11 stall horse barn with auto waterers so your product would not eliminate the huge 350 gallon storage tank that also serves as a contact tank for chlorinating the water to remove iron or the carbon filter to remove the chlorine.

I will not comment further since the two technologies do compete in certain applications and this is your forum.

I wish you all the best with the stop cycle valve product. I may buy one myself for a few apartments I own.

Phil
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
VFD's certainly have lots of good applications. Just that pumping cool, clean, water, with a centrifugal pump is not one of them. I am very aware of the "federal mandates". There are also federal mandates to add ethanol to our gasoline, even though it is energy negative. There are also subsidies and tax breaks given to wind energy companies, even though the wind generators have a 30 year payout and have to be completely rebuilt every 15 years, so they are also energy negative. Another "federal mandate" was to make manufacturers take all the lead out of plumbing, even though lead is not the problem. The government employees who don't know any better than to put caustic water into our pipelines are the problem.

These same government employees don't know how to properly use the Affinity law, and do not know how to read a pump curve. They basically let manufacturers guide the tests for VFD's, which is like letting the fox guard the hen house. I have also read the articles that show the "green energy" buildings built to "government specs" over the last few years are actually using more energy, not less. When you install a bunch of VFD's in a building thinking they are going to save energy, the energy costs actually goes up. They see the amps go down when the motor slows down, but they do not understand that it actually increases the cost per gallon produced, which is the real work, not just spinning the pump.

I have read every "test" and every article I can find on how VFD's supposedly save energy. I have yet to find an accurate article or test. When you read the fine print, the systems pressure was reduced, a jockey pump was added, or there was some other reason for the energy savings, yet the VFD added at the time incorrectly gets all the credit. It has to do with people seeing the amps decrease when the motor/pump speed is reduced, yet not realizing that it is actually increasing the cost per gallon produced.

You are correct that valving a full speed pump does not decrease the power consumption as much as varying the speed. But there is very little difference like 6-8 percent. But the same pump running at full speed is about 5% more efficient without a VFD. Over the full flow range valving a full speed pump can be more efficient, because it doesn't reduce efficiency at high flow like a VFD does.

The old joke about "I am with the government and am here to help you" is not funny anymore. I have lost so much faith in my government making intelligent decisions, that I no longer believe a word they say. If they outlaw incandescent light bulbs, I go out and stock up on them before they are no longer available. If they give me tax credits on solar panels, I know it is because the technology won't survive on its own accord.

Here are a couple of pump curves. Notice that the horsepower for the variable speed pump at 15 GPM flow is 1.515 HP, while the normal full speed pump only uses 1.392 HP.
VFD vrs CSV at 15 GPM.jpg



Then when comparing reducing the speed of the pump with a VFD to restricting a normal speed pump with a valve, at 2 GPM flow the VFD uses 0.583 HP, while the normal pump restricted with a valve uses only 0.629 HP.

VFD vrs CSV at 2 GPM.jpg
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
My well pump is 350 ft from the house and I need a booster at the house to maintain good pressure. Your valve will not boost pressure. I also have a 11 stall horse barn with auto waterers so your product would not eliminate the huge 350 gallon storage tank that also serves as a contact tank for chlorinating the water to remove iron or the carbon filter to remove the chlorine.

I will not comment further since the two technologies do compete in certain applications and this is your forum.

I wish you all the best with the stop cycle valve product. I may buy one myself for a few apartments I own.

Phil

If the 350' of line is too small, you will lose pressure. But you can turn up the pressure of the CSV and pressure switch at the well pump, then you should not have to boost from the other end. If you lose say 20 PSI to friction loss in the long pipe, you just need to turn the CSV and pressure switch up an additional 20 PSI to make up for the loss. Contact tanks do not have air in them, and do not store water. I have run larger pipe in the ground to give the same effect as a contact tank. A short piece of 12" pipe or so after the chlorine pump can make a good contact tank. Contact tanks and filters have nothing to do with what a CSV or the pump system is doing.

This is Terry's forum. I only help with the pump and well section. But I am glad to discuss these things with you as I have very few people who understand enough to have such a discussion. The engineers for the government agencies won't even discuss this with me. They just get that deer in the headlights look in their face and tell me I am entitled to my own opinion. The problem is, it is not just my opinion. Pump curves don't lie. You just have to know how to read them.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks