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Small Cabin Forum / Off-Grid Living / Flojet water pump question
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paulz
Member
# Posted: 8 Jun 2016 09:11pm
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Finally getting around to hooking up my L5 heater and Flojet pump. My water tank is above my cabin and I have been using gravity feed so far, and was hoping to continue doing so some of the time but I tried to blow through the Floject and can't. Does this mean when I install the Flojet it has to have power to it all the time, otherwise no water?

hamish
Member
# Posted: 8 Jun 2016 09:48pm
Reply 


That is correct for it is a vane style pump.

Just add in a 2 way splitter in the water line and problem solved.

paulz
Member
# Posted: 8 Jun 2016 10:39pm
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Thanks Hammish. Do you mean a bypass line around the pump, with a valve in it, so when the valve is open the water bypasses the pump? That would work but my pump will be outside (since the L5 is and the pump has to be prior to it), so I would have to go outside to turn the valve. Which is OK I guess.

littlesalmon4
Member
# Posted: 9 Jun 2016 11:17am
Reply 


The valve can be inside. The y for the water would have to be before the pump.

paulz
Member
# Posted: 9 Jun 2016 12:09pm
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I don't see how. This is how I have it laid out, and where I think the bypass and valve need to be. Is there another way?
Capture.JPG
Capture.JPG


morock
Member
# Posted: 9 Jun 2016 12:23pm
Reply 


Use a check valve and your done. No on-off required.

littlesalmon4
Member
# Posted: 9 Jun 2016 12:54pm
Reply 


What systems do you want on the pump?

sparky30_06
Member
# Posted: 9 Jun 2016 01:41pm
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use a flap style check valve and not a spring style. Spring style could require more pressure to open than the gravity feed system can supply.

paulz
Member
# Posted: 9 Jun 2016 02:31pm
Reply 


Everything on the pump when in use.

So with a check valve the water runs through the bypass, and when the pump is powered up and a faucet is opened, the pressure of the pump closes the check valve?

hamish
Member
# Posted: 9 Jun 2016 09:14pm
Reply 


The valve needs to be before the inlet to the pump, it will be a pump or no-pump valve. A check valve will most likely not generate enough head pressure for the pump, but will keep the lines primed as will gravity for which you already have.................

sparky30_06
Member
# Posted: 10 Jun 2016 06:55am
Reply 


paulz correct. think of the check valve are a one way street.

scenario #1 .
pump is electrically disconnected from the system so you only have gravity pressure. you flush the toilet, water can't flow threw the pump so it goes threw the check valve.

scenario #2
pump is electrically connected in the system. you flush the toilet, water pressure drops pump kicks on pressuring the line. The water tries to flow against the check valve and back to the tank but it closes stopping flow in that directing.

paulz
Member
# Posted: 10 Jun 2016 09:52am
Reply 


sparky, under scenario #2 (no pun intended ) when the toilet is flushed, water can still flow through the check valve faster than the toilet fills, thereby retaining enough pressure in the system to prevent the pump from turning on? I guess that would depend on the kick in pressure setting of the pump. Might actually be good: if I turn on the sink a little bit I get water but no pump, turn it on more for faster fill and pump kicks in.

sparky30_06
Member
# Posted: 10 Jun 2016 11:58am
Reply 


to maintain pressure in the system you need the pump running or the tank elevated to create head pressure. Water creates about .433 psi per foot of head.
So with that being said, if you water level inside the tank is 100 feet off the ground the water pressure at ground level would be about 43 psi.

So lets say your pump pressured switch is set to turn on at 20 psi and shut off at 40 psi. you would need 50 ft of head pressure to maintain 25 psi. Now if the flow rate increased and pressure dropped your pump would kick in acting like a booster at that point.

So unless you have a water tower the pump will probably be kicking on every time you have water flow.

Now if you only wanted the water pressure boosted when running the shower, for example, why not install a switch to control the power to the pump?
Then you would have your gravity system for the sink and toilet so not to use up battery power.

paulz
Member
# Posted: 10 Jun 2016 08:47pm
Reply 


Sounds good. Took a trip to the hardware store today to find a valve but by the time I got all the other stuff I needed I forgot. Some kind of gate valve that can hook to CPVC hopefully.

sparky30_06
Member
# Posted: 11 Jun 2016 09:25am
Reply 


http://www.homedepot.com/p/3-4-in-Brass-FPT-x-FPT-Swing-Check-Valve-240-2-34-EB/20581 6264

you would need MNTP adaptors.

if it's a spring style check see what the cracking pressure is. most are around 1 psi but some are higher.

How high the water level to ground in your storage tank??

paulz
Member
# Posted: 11 Jun 2016 07:45pm
Reply 


Bottom of tank is 15ft above cabin floor. Thanks for the valve link.

paulz
Member
# Posted: 19 Jun 2016 07:09pm
Reply 


Success! The check valve works perfectly, gravity feed when pump off. I jumpered a battery to the pump, shuts check valve and works great!

Thanks for all the replies.
0619160742.jpg
0619160742.jpg


sparky30_06
Member
# Posted: 20 Jun 2016 06:43am
Reply 


see easy!!!! Glad it works for you.

paulz
Member
# Posted: 27 Jul 2016 09:07pm
Reply 


My water system has been working great, I just have one concern; the pump comes on for a second every couple of minutes. For the life of me I cannot find a leak. I have shut off the toilet valve, the sink valves, the water heater (L5) input valve..

I'm starting to sheetrock the bathroom so want to make sure nothing is wrong first, though the pipes and studs are all bone dry.

Thought it might be the gate valve leaking, which would pump water back towards the tank, but I have a valve on the input pipe and shutting that off doesn't help.

Just wondering what troubleshooting I might do other than looking for leaks.

Just
Member
# Posted: 27 Jul 2016 10:03pm
Reply 


could be something in the pump ie. dirt, stone, bit of plastic . they are not hard to take apart to look .

sparky30_06
Member
# Posted: 28 Jul 2016 11:25am
Reply 


if you isolated the check valve and it's still doing it, possibly the check valve in the pump is letting pressure slip past and go back to your tank. Do you have a pressure gauge in the system??

paulz
Member
# Posted: 28 Jul 2016 12:00pm
Reply 


Thanks guys. I have no filter before the pump, never thought of that. Also a pressure gauge, good ideas.

NorthRick
Member
# Posted: 28 Jul 2016 08:17pm
Reply 


You might want the filter before both the pump and the check valve. A small piece of debris could keep the check valve from closing tightly.

sparky30_06
Member
# Posted: 29 Jul 2016 06:42am
Reply 


a flap check valve can get trash caught in it. unfortunately with the low pressure from your gravity system you can't use a spring loaded check they can seal against trash a tad better.

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