Don't put a check valve between the pump and the pressure tank

Ok, I thought I knew what I was doing...  I am adding a hand pump to my house plumbing so that if the power is out I can still pump water from my shallow (sand point) well.

To implement it, I modified my plumbing to add a Tee between the inlet of the pump and the check valve at the top of the well.  This Tee feeds the inlet of the hand pump.  After the electric pump I added a check valve to keep the hand pump from pushing water back through the electric pump in a circle.  While doing this I had the electric pump removed and partially drained so I had to reprime it to get it working again.

Long story short, the hand pump has a leak (due to my lack of skills) so I pulled it out and capped the unions while I figure that out.

Now that I turn the electric pump on, when it hits 50psi, it kicks on and of repeatedly until I flip off the breaker.  Son of a .....!

I thought that maybe there was too much air in the pipes so I purged them really good and tried again.  Same problem.

Could the new check valve between the pump and the pressure tank be the problem?  Or is my new bit of piping on the inlet side of the pump causing issues?  Or did something unrelated happen while I was messing with it all?

Thanks for any guidance I can get!!!

I can't speak for the possibility of your check-valve being the culprit or involved in some way, but the symptom you are describing is one that we've dealt with before on a similar system.  Ours is a submerged electric pump system with a similar ballast for pressurizing the system.  At some point, the inflatable diaphram inside the ballast bell can give out.....and then it's no longer able to provide pressure for your system.  What this means is that your pump is now a slave to you opening your tap.....and the pump will have to run constantly as long as the tap is open.  My understanding is that pump motors are not meant to be 'constant' duty, just 'intermittent' duty.  They are fine charging up the ballast, after which they can shut down temporarily while the ballast does the work of providing temporary pressure in the system.  Maybe some aspect of that happening here?.....Perhaps the ballast diaphram is partially shot in someway and working enough for rapid cycling, but not enough to keep the pump off?  We had a plumber come out to troubleshoot and it was common enough with them that they had all items on hand for the fix.  Hope you find a solution soon!...

It looks like your pressure control is integral with the pump, so whatever the pressure is inside the pump will tell it to run or stop. What is the purpose of the new check valve after the pump? Are you trying to prevent water from flowing back from the tank into the hand pump? Does the hand pump feed into the house system, or just supply a faucet? What is the flow direction of the new check valve?

I don't understand the reason for the new check valve, and have a feeling it is not needed even if everything is installed well. A check valve after the pump will keep the pump from seeing the pressure in the tank, and if the check valve before the pump is the slightest bit leaky, the pump would see its pressure draining away quickly and turning on, then immediately stopping because the tank is already full.

If the hand pump is meant to simply draw some water from the well and deliver it to a faucet, it should not matter what the rest of the system pressure is (as long as no faucets are open; that would pull air back through the open faucet into the system piping.)

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Examining the pictures as well as the text again, I understand your system now. You put the check valve in the wrong place. Instead of at the outlet of the pump, it should be in the pipe between the new tee and the pump, so the hand pump can pressurize the whole system. It doesn't matter if the pump gets pressure from the other end, the same think happens in an ordinary system when the tank is full and the pump is off.

I should have included a picture of it with the hand pump still installed...  The intent is for the hand pump to be able to pressurize the system and deliver water to any faucet in the house.  I'm not sure if it can develop enough pressure, we'll see.

My hope is that the original electric pump can continue to work all the time and run the house.  But when the power is out, the hand pump can suck water out of the shallow well and also pump into the system.  The issue is that either pump could possibly pump water in a circle using the other pump's piping.  The hand pump has a check valve in it so that keeps the electric pump from pushing a circle.  But I wasn't sure about if the hand pump could pump water backwards through the electric pump.  So that's why I added that check valve.

And yes, it's oriented so the flow goes towards the pressure tank.  And yes, the pump pressure switch measures the pressure in the pump housing.  So that's why I'm not exactly sure what's going on.  Seems like once the pump kicks off it wouldn't have a reason to kick on until the pressure drops below 30.

Then again, the pressure gauge now reads 0psi even when there is pressure in the tank (due to the check valve).  So maybe the pump kicks off fast, the new check valve springs shut faster than the bigger original check valve and the pressure in that contained bit of piping drops below 30psi.  Now that I type that out, I think that's the issue.  Plus a guy at the bar tonight said to remove the check valve and see if it fixes it.

So in the morning I'll pick up a ball valve to replace the check valve.  Then if the power's out I just have to close that valve to use the hand pump...

FYI, I did test the hand pump and it does pull water and put some in the pressure tank.  It easily fills a bucket.  But it was leaking too badly to see what max pressure it could deliver.

And thanks John, that's a problem I have had when the pressure tank was bad.  But in this case it's not what's going on.  

Changed the check valve over to a full flow ball valve and that fixed it.  The lady at Menards said that was the problem as well.  Woo Hoo!  

Mike Haasl wrote:So in the morning I'll pick up a ball valve to replace the check valve.  Then if the power's out I just have to close that valve to use the hand pump...

My thought as well... although, you might want to test out what the pressure switch/pump does when that ball valve is shut, and also when you are hand pumping.
You might also want to switch off the power to the pump during an outage, so that when power is restored the pump doesn't start running against that closed ball valve.
You might want to add ball valves to isolate the hand pump so that it isn't pressurized under normal conditions? also for repairs.

Yeah, I'll turn off the pump if the power is out and we're using the hand pump.  And yes, in retrospect I should have put valves on the inlet and outlet of the hand pump.  After I get it patched up and put in again, I'll probably modify the plumbing to add those valves.

It's a pity that check valve didn't work.  Then either pump could've run at the same time.  With my plumbing layout, I think I could put a check valve on the inlet of the pump and that would solve my problem without causing the on/off/on/off/on problem.

Glad you got it sorted. Yes, a check valve right at the pump inlet would automatically and safely cover all operating situations.

mike, I notice you are using all galvanised elbows etc.
Here in Australia we can get, and I use black plastic threaded fittings that are very well priced and do not corrode with the water as the galvanised ones do.
Have you thought of using them?

I'm not sure if we have those over here John...  I'm not really sure what people use on new installations, I was copying the style that was there.  With the vibration of the pump I like the steel but I don't like what the insides of the older pipe pieces looked like.

For potable water, any metal piping is best as brass/bronze or stainless steel. Brass fittings are a bit more expensive than galvanized, but will last longer and will not corrode at the threads and be impossible to disassemble.

Hmmm... You may want to ask the locals about pipes for water. In my small town copper is against code. Something about the city water degrades the pipes. Whole housing complexes had horrible leaks. I don't know if it is an aquifer or water treatment problem. I have chosen to stay away from copper even though I have a well system.

Mike Haasl wrote:Ok, I thought I knew what I was doing...  I am adding a hand pump to my house plumbing so that if the power is out I can still pump water from my shallow (sand point) well.

Forgive me as I'm scratching my head now at this clip from the original lead-in post.  Mike, is this water source for your drinking water or is this dedicated for some other use?  It suddenly occured to me that your (final) set-up would be a great way around sinking parallel hand-pump piping next to the powered pump piping within the same well casing as some solutions offer to do (SimplePumpTm?......or do they tap into the pre-existing well pipe?).  But confirm for me that trying to use your set-up would or would not work for currently-installed well depth of 160 - 180 ft underground.  SimplePump seems to offer a deep-well version, but that appears to require a parallel pipe that runs the entire depth of the well. (?) That would simply be too deep for an above-ground hand pump to pull to the surface, yes?

Hi Glenn, this is my only water source for the house, a shallow sand point well.  I don't know the depth but I'm guessing 15-20' down.  So this hand pump can overcome that amount of lift to move the water.  A deep well (over 32' down) would need some fancier style of pump to overcome the lift.

My goal is to be able to pump water 99.9% of the time with the electric pump.  If the power goes out, I can now close the ball valve and then manually pump water out of the same well and distribute it around my house.  I just got it reassembled this morning and will test the strength of the hand pump later today or tomorrow.  Then I'll know what pressure I can develop.  I hope it can do 30+ psi but we'll see.  It easily pumps water out a spigot by the pump so even if it can't develop much pressure it can easily fill buckets during power outages.

Glen, the plastic pipes I referred to are suitable for potable water.
They are made from Polyethylene which is  considered one of the safest plastics.
From Polyethylene plastic safety

Too often people jump to conclusions about products.

Your pressure switch is on the wrong side of your discharge check valve. If you moved your switch. your piping manifold would be fine. They do make tapped check valves that would accept a 1/4" nipple and pressure switch.

Shallow well pumps such as this are commonly built with the pressure switch included. Moving the pressure switch to the tank inlet as is typical for a deep well installation would solve the cycling issue, but the real best solution would be check valves at the inlets of both the electric and hand pumps, so that either would be usable without any valve operation.

John Daley, my statement "any metal piping is best as..." was poorly worded. What I meant was that if you have metal piping, the best kind would be brass/bronze or stainless. There are some places where the water is corrosive to copper, so obviously brass or bronze would not be suitable there.
I have no issue with plastic piping or fittings aside from the fact that metal is generally stronger and often more durable.

Mike, how  is the hand pump working out?

It kinda worked!  I screwed up gluing together the hand pump so it's piston flapper leaks a bit internally.  But I can hand pump up to 13psi.  To make that usable I'd have to depressurize the pressure tank which I don't want to do unless it's really needed.