Unusual Pressure Drop on Higher Demand

[Haymaker]

Hello,

I am having some challenges with my water pressure when I am demanding a higher amount of water. I have always been able to run 2 garden hoses at the same time with excellent water pressure and since recently installing a new pump (same kind as before) this has changed. I offer the following information on my system:

1/ Well depth is 272 feet. Just tested at 10 US gallons per minute.

2/ Grundfos 1 HP submersible pump.

3/ Square D 40/60 pressure switch.

4/ Well Mate WM20 Pressure Tank (with bladder)

5/ System has a good pressure guage in-line just before the pressure tank.

When the water demand is "not" higher the pressure switch properly kicks in at 40 lbs, builds up pressure and switches off at 60 lbs.

When the water demand is higher the pressure switch does kick in at 40 lbs but the pressure will drop to around 20 lbs until the demand eases up. This would never happen before, as even with "more than" 2 garden hoses running at once it would always build pressure back up to 60 lbs after the switch would kick in at 40 lbs.

My pressure tank is set at approximately 39 lbs pressure but I am not 100% certain my hand guage that I checked it with is completely accurate (I have a feeling it could be out by as much as 4 or 5 lbs which could be causing the problem). Is there any way to calibrate my hand guage somehow to ensure it's accuracy... perhaps with the in-line guage on the system that I know is accurate?

There was some "fine" sand coming through my system before the pump was replaced but I have an in-line filter (located after the pressure tank) that would catch it. There is no sign of sand since the new pump has been installed, but perhaps there is some previous sand build-up in the check valves or somewhere else restricting water flow? I do know that the pump does not have any sand getting into the intake area any more, as I had to bring it up after 6 weeks due to a manufacturer's defect whereby they replaced the pump free of charge.

The system was installed about 9 1/2 years ago and I was told that my pressure tank may fail at about this age, but there is no sign of water above the bladder and no water vapour comes out of the air valve if I am letting air out. Is it possible that there could be a "slight" failure in the pressure tank and it is on it's way out or is this something that would immediately happen and shut down the system completely? If a pin-hole leak is possible perhaps I should just replace my pressure tank and this will correct my problem?

Thanks in advance for any assistance / recommendation anyone can provide. This is a great forum by the way and I am sure glad I found it!

 

[Gary Slusser]

Pumps come in two parts, the motor rated in hp and the wet end rated in gpm.

What gpm pump did you have and what gpm is this one.

If this pump is rated at a lower gpm, it won't produce as much water at higher gpm flow rates.

 

[Sponsor]

 

[Speedbump]

Grundfos impellers are stainless steel. Stainless is softer than most plastics these days. If your well is pumping much sand, it could have eaten the impellers, causing a reduction in production.

It could also be a plugged well screen if your well has one. I would think ten gallons per minute would be sufficient for two hoses.

bob...

 

[Haymaker]

Thanks for the replies.

My new pump is exactly the same as my old pump so there is no change with the GPM rating.

There is no sand coming through the system now and none since the new pump was installed about two weeks ago. For the first 5 years I never had sand come through the system but then I had to replace the pump. When it was replaced they did not re-install the rigid dip tube piping when they dropped it back down the well casing and therefore the poly pipe was able to stretch which put it slightly lower than the original pump. Over the next 3.5 years with my second pump we had to install an in-line filter to block fine sand from getting into the house and it seemed to work fine. The second pump started to reduce the amount of water it was pumping and when we pulled it out of the well it was obvious that the pump intake was starting to become completely clogged with sand. We then replaced the pump (now pump #3) and replaced the old poly piping with rigid piping. This pump #3 was now at the same depth as my original pump #1 and there was no sign of sand getting into the system and all seemed to be working great again. Six weeks later the pump just stopped working and we had to pull it up again. We determined that it was a defective pump and have now installed another new one (now pump #4). Pump #4 has been working fine since it got installed a couple of weeks ago except for the pressure drop (below 40 lbs) when there is higher demand required.

A neighbor of mine had this same sort of problem and it turned out to be an adjustment required to the pressure in the pressure tank, but I think mine is OK unless my hand held guage is not accurate. Like I said it could be out by as much as 4 or 5 lbs but I am not sure unless I can calibrate it somehow with my in-line pressure guage that I know is accurate.

Do you think that a possible 4 to 5 lb variance in my pressure tank could be causing the problem?

Thanks again for your help.

 

[Speedbump]

Poly pipe doesn't stretch much and where the pump is in the well has nothing whatsoever to do with pumping sand.

What your saying makes no sense. Pump screens don't get clogged with sand, the sand goes right through them and through the impellers and on into the home or filter. Sand destroys impellers over time but not in two weeks.

Who is doing this work. You, or a Well Driller? What kind of filter is it your using to catch sand?

bob...

 

[Gary Slusser]

I agree with Bob. So what gpm pump do you have?

 

[Haymaker]

Bob,

I apologize if what I am stating is not making sense. I have a contractor who looks after my well for me who is very good but unfortunately I live in a very remote area and he has to travel quite a distance to help me. I try to assist he and his crew when they have to do work on the well and I am simply trying to explain what I have observed and provide some background information on my system. With this being said I am by no means an expert on the subject and that is why I am looking for some help on this forum, as I just don't want to bother my contractor again if there might be a simple fix to the problem or something I can try in an effort to resolve the situation.

Unfortunately when my most recent pump #4 was installed two weeks ago my contractor was in a rush and had to get back home. He did not have time to look at the pressure tank or switch settings before he left. I did have an electrician install a new pressure switch after pump #3 failed and I also bled air from the pressure tank to see if there was any sign that it had failed. I used my compressor to refill the pressure tank to 39 lbs but again, I am not confident that my hand held guage was accurate when I did this and perhaps this is my problem.

Given your comment about sand destroying impellers over time and not in two weeks I would then assume this likley has nothing to do with sand getting into my present pump but I just wanted to provide some background information. Your comment also supports my pump #2 pretty much dying after only 3.5 years of operation. However, when we went to pull my pump #2 out of the well about 6 to 8 weeks ago it was stuck in like quick sand and it took hours to get out. We finally had to flush the well casing with a garden hose to get it free. Perhaps this would explain the sand build-up that was quite evident on the intake fins of the pump when we got it out. We had absolutely no problem pulling out the defective pump #3 two weeks ago and there was no evidence of sand in the intake fins or in my whole house filter.

I am using a Rain Fresh High Flow Whole House Water Filter Model #BH010 and it handles up to 100 psi and handles a flow rate of up to 15 gallons per minute. The actual filter I use inside the housing is a GE Smartwater FXHSC #4 that is meant for sand, sediment or rust and is compatible with the Rain Fresh housing. This #4 filter has a nominal particulate reduction rating so it does not impede the water flow very much at all.

To answer Gary's question about the GPM rating on my Grundfos pump, when I look in the manual it has a table that states a "Flow Range" of 3 to 15 GPM. If that is not what you are asking for then just let me know and I will look elsewhere for the information.

Thanks again for all your help.

 

[Speedbump]

You may find out that all these so called "Whole house Filters" are the whole problem. If you really want to filter water, they are not what you should be using. Those were designed for one faucet only. When they didn't catch on that way, the manufacturers started calling them "Whole house Filters" and look how much money they made.

bob...

 

[hj]

pressure

Unless you have something restricting the flow between the pump and the pressure tank, once the pump comes on the tank is taken out of the loop and you are running entirely on the pump discharge. If that is inadequate for the demand the pressure will continue to drop until it may reach a point where demand and output are equalized. The pump will continue to run until the demand drops and it can again pressurize the tank and turn off.

 

[Haymaker]

Thanks for your replies.

I have now checked my pressure tank with an accurate guage and it is at 38 lbs.

I am able to bypass my in-line "whole house" filter completely and tried that but still no difference.

Given hj's comment the only thing that is installed between the pump and the pressure tank is first, the main shut-off for water coming in through the main line and then a brass check valve. It then stems off into the pressure tank/switch components. Is it possible that either the check valve or the shut off handle component could be causing the problem? Any chance there could be sand build-up in either of those components (from when I was getting sand through my system a while ago) that would cause this sudden restricted water flow?

I also read on another thread in the forum that a somewhat similar issue was resolved after the person cleaned out the small water stem pipe that connects to the underside of the pressure switch. He did find gunk built up inside it when he blew it out.

Any chance there could be sand build-up in the pressure tank that would affect the flow?

Do you think the situation might improve if I changed the pressure switch to a 30/50?

These are all just guesses on my part as I am not sure what else to do here, but at least my family are still able to function fine with the water we are currently getting.

Once again, if I turn on 2 garden hoses at once the pressure switch will kick in at 40 lbs and then the pressure will suddenly drop to about 10 lbs and then hold steady at about 18 to 20 lbs. As soon as I turn off "one" hose the pressure immediately jumps back up to 40 lbs and climbs slowly from there. I am also not 100% sure, but it appears to me that the pressure is taking longer to build back up to 60 lbs than it used to (once I have turned everything off).

Thanks for any suggestions you might have.

 

[Gary Slusser]

Given hj's comment the only thing that is installed between the pump and the pressure tank is first, the main shut-off for water coming in through the main line and then a brass check valve.

There should not be a shut off valve between the pump and the pressure tank. Yes the washer could be partially blocking flow.

An above ground check valve can hide evidence of a leak between it and the one in/on the outlet of a submersible pump. A leak may be your problem. I'd remove the stop valve and that check valve.

A pressure tank can not hold sand/dirt to be able to restrict flow. And you only get flow out of the tank until the pump comes on, remember? A galvanized nipple or pipe may be blocked with rust. The tank should be on a tee, in the middle of the tee, so the water can go past the tank in a straight line. Otherwise, when the pump comes on, the water direction has to change direction 180*.

Your problem is not your tank or pressure switch. It's either the water level in the well goes down to where the pump can't deliver all you want to use, are you in a drought area, or, there is something wrong with the pump or, you have a leak, probably in the drop pipe or a fitting.

Once again, if I turn on 2 garden hoses at once the pressure switch will kick in at 40 lbs and then the pressure will suddenly drop to about 10 lbs and then hold steady at about 18 to 20 lbs. As soon as I turn off "one" hose the pressure immediately jumps back up to 40 lbs and climbs slowly from there. I am also not 100% sure, but it appears to me that the pressure is taking longer to build back up to 60 lbs than it used to (once I have turned everything off).

That proves what I am saying.

 

[Speedbump]

Given hj's comment the only thing that is installed between the pump and the pressure tank is first, the main shut-off for water coming in through the main line and then a brass check valve.

This is obviously a home owner install. I can't imagine a pro putting anything like a valve between the pump and tank/pressure switch. Let alone an in line filter. Then a check valve to top it off. If you really want to get to the root of the problem. Remove all that junk and have no items between the pump and tank.

bob...

 

[Haymaker]

Hi,

Before I pay a plumber to come in and remove the shut-off and check valve installed "before" the pressure tank, I thought I should attach some pictures of what I have in my crawlspace so you can see the set-up first hand (hopefully I have attached the photos properly).

The in-line filter is installed "after" the pressure tank was only installed after we ran into the problem where sand was getting into our main house water lines (with my pump #2). This is no longer a problem and as suggested, the filter has now been completely bypassed as you can see in the photos.

Everything on the right hand side of the pressure tank is where the main line from the pump is coming into the house. Everything on the left is where the main line splits off to service our main house, our detached garage, our barn and a seperate field faucet.

P.S. I am the original owner of my home and trust me, I did not install this but as I stated earlier, I live in a very remote area and good help is sometimes hard to find.

Thanks again.

 

[Haymaker]

P.S.

I was just told by a plumber friend tonight that sand "can" definatley build up in a check valve if I have had a problem with sand coming into the sytsem in the past and also with the shut off washer as well (just as Gary said could be a possibility).

In his opinion having a shut off valve before the pressure tank is beneficial but he is also questioning any need for the check valve.

Thanks!

 

[Gary Slusser]

The check valve is not the standard type used on wells; or at least I've never seen one like that on a well. It looks like it could hold some sand but, sand is not your problem.

And why don't you learn how to solder and do this simple job yourself?

 

[Haymaker]

Gary,

Thanks for your feedback, apparently from the responses I have had so far anything that is between my well pump and my pressure tank could be the problem and considering there are only two things (a shut off valve and a check valve) then I would think sand in the check valve might be a strong possibility and could be restricting water flow.

As for your comment "and why don't you learn how to solder and do this simple job yourself" WTF are you talking about and where are you coming from? What simple job are you referring too? You guys keep referring to this as a "home owner install" and make numerous other insults on the information I have simply tried to provide (now including pictures)... I have always tried to hire professionals to help me and am simply looking for some additional "professional" advice & suggestions. I am not a professional in this business and have never claimed to be. All I have done is give you as much information as I can... the same as what you ask from every other person on this forum when they have a problem. After reading many, many threads on this forum I thought you (especially you) were simply trying to help folks that are not professional's in your industry? Anyway, maybe I am wrong and thanks for trying.

At this point, if anyone else can offer some constructive feedback and not insult my lack of being able to solder something or whatever else, please let me know.

Gary, while I appreciate the advice you have provided to try and help me... if you ever require any information on how to "simply" cut hay for a living, please let me know... I can definatley help you in that department... as I am expert!! You are very condescending and I really don't appreciate some of the comments you have made towards me or my questions.

Thanks to anyone who can actually help me or suggest something in a positive/constructive manner, otherwise I am definately on the wrong forum and will seek advice elsewhere.

 

[hj]

pressure

Unless there is some factor not visible in the pictures, you have no restriction between the pump and the house system. Therefore, the most likely cause of your problem is a pump that cannot produce the amount of water you need. It may be what is plugged up. A very remote possibility is a well that does not have enough capacity along with a pump that cannot lift the water high enough so the water level drops to the point where 40 psi is all the pump can produce on a steady basis.

 

[Gary Slusser]

Gary,

Thanks for your feedback, apparently from the responses I have had so far anything that is between my well pump and my pressure tank could be the problem and considering there are only two things (a shut off valve and a check valve) then I would think sand in the check valve might be a strong possibility and could be restricting water flow.

There should never be anything between a pump and its pressure switch. Period. As to trapped sand being your problem, let me repeat myself, you're wrong.

As for your comment "and why don't you learn how to solder and do this simple job yourself" WTF are you talking about and where are you coming from? What simple job are you referring too?

It was a friendly question. I was refering to you doing the plumbing to remove the check valve and stop valve. I assumed that is why you were going to hire the professional.

You guys keep referring to this as a "home owner install" and make numerous other insults on the information I have simply tried to provide (now including pictures)... I have always tried to hire professionals to help me and am simply looking for some additional "professional" advice & suggestions.

Your professional screwed up putting the check and stop valves between the pump and the switch.

All I have done is give you as much information as I can... the same as what you ask from every other person on this forum when they have a problem. After reading many, many threads on this forum I thought you (especially you) were simply trying to help folks that are not professional's in your industry? Anyway, maybe I am wrong and thanks for trying.

Yeah you're wrong. I help people that want to help themselves or not or just want info concerning their problems; you seem to not want to accept anything but trapped sand... I believe that encouraging you or anyone else in a DIY forum to learn how to solder so as they can do a simple plumbing job is helpful. I've been doing this for a long time. If you don't want to do that, so be it, but to call me names is a mistake because I was trying to be helpful; it is simple plumbing whether.

At this point, if anyone else can offer some constructive feedback and not insult my lack of being able to solder something or whatever else, please let me know.

I guess you want the cause of your problem to be the sand trapped in the the system and don't want to hear anything else. It's not sand trapped anywhere.

Gary, while I appreciate the advice you have provided to try and help me..... You are very condescending and I really don't appreciate some of the comments you have made towards me or my questions.

Really? I don't see it that way or you'd be accepting my advice. My soldering comment was to say, learning to do it yourself is easy and it is simple plumbing and you go off the deep end on me.

Thanks to anyone who can actually help me or suggest something in a positive/constructive manner, otherwise I am definately on the wrong forum and will seek advice elsewhere.

I'm sure you can find someone on some other forum to agree it is trapped sand, so go for it.

 

[Speedbump]

That is a swing check valve. It's main use is in sewage pumping applications where pressure is not a problem and items the same size as the pipe are allowed to pass through. Talk about water hammer in a pressure system. Like Gary said, there should never be a check valve or a stop valve of any kind in the line between the well and pressure tank/pressure switch. I agree with Gary in that there is no sand problem causing your low pressure problem. That big white so called whole house filter could be a problem though.

If you had enough sand to cause a problem with your pressure, your lines would be full and your fixtures would be plugged solid with sand. Otherwise a little bit of sand comes through just like the water does.

By the way, Gary was trying to be helpful, if you thought he was bad mouthing you, you apparently have the problem.

bob...

 

[Haymaker]

Hi,

Thanks to you all for your comments and suggestions pertaining to my situation. At this point I think I will just double check with my well contractor and if he is in agreement then I'll have my plumber come in and remove the check valve and shut off that is before the pressure tank, as all of you seem to agree that there should be nothing between my pump and the tank. These are components that a plumber installed when we were originally building and not my well contractor. Who knows, there may be something wrong with either of these components (besides sand), but at least by removing them it will eliminate that possibility and also have the system set up as you have all suggested. While I now understand why Gary suggested to do this myself, I would just feel better having a professional in your field come in to ensure it gets done properly. With respect to the whole house filter, I have completely bypassed it so I don't think it is creating any problem/restriction at this point.

Thanks again to you all for trying to help and I will let you know if the situation gets resolved.