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Topic: Fresh Water Pump  (Read 2500 times) previous topic - next topic

Re: Fresh Water Pump

Reply #21 –
John,

Suspect you already know this, but to check/pressurize accumulator pressure:

Turn off pump and shore water.
Open faucet to bleed off pressure
You will need a small screwdriver, standard automotive tire gauge and either bicycle air pump or other air source.

Remove the plastic cap from the tank valve stem.
Momentarily touch the tip of the screwdriver to the center stem-- just long enough to verify that you are getting AIR, not water out.  If water, the accumulator is dead and needs to be replaced.

Correct PSI is pump CUT-IN PSI less 2 PSI.  So for the old pumps with 25 PSI cut-in PSI, 23 PSI.

Re: Fresh Water Pump

Reply #22 –
Thanks Brett!  Will check the tank.
John M.

Re: Fresh Water Pump

Reply #23 –
All that's needed is a vertical chamber in the pressure side of the line. A 3 in by 6in pipe with a tight cap will soften the pump pulse action. The pump may last  longer and will make less noise and the shower will feel smoother.

Re: Fresh Water Pump

Reply #24 –
Yup, a homemade accumulator.

Re: Fresh Water Pump

Reply #25 –
I'm thinking that my issue is the size of my accumulator tank.  It may be too large for my pump.  I replaced my small water logged tank with a large 2 gallon tank 2 years ago.  Maybe bigger is not always better. The pressure is great when you first open the faucet then decreases with long use.  We have a long run with low pressure before the pump kicks.
John M

Re: Fresh Water Pump

Reply #26 –
2 gallon accumulator should be no problem.

Have you had a chance to check the accumulator PSI?

Re: Fresh Water Pump

Reply #27 –
Quote from: John Morales –
We have a long run with low pressure before the pump kicks.
Size of pressure tank should not affect pump cut-in point.  Sounds to me more like the pump is "reluctant" to start for some reason.

If you have a restriction somewhere in the water lines between pump and faucet, the pump might be "seeing" high pressure while at the faucet you experience low pressure.  This might delay pump cut-in...?

Wonder if it would be worthwhile to rig up a simple water pressure test manifold with a pressure gauge.  Connect it directly to pump outlet.  Check cut-in and cut-out pressures. 

Re: Fresh Water Pump

Reply #28 –
Quote
to avoid the surging of the pump on low flow.

I too had that issue when I removed the accumulator a few months back. I found that adjusting the cut in point on the SureFlo cured that annoyance. On another rig I removed the tank and installed an AquaJet. That one didn't require an adjustment.
jor

Re: Fresh Water Pump

Reply #29 –
Re: John's adjusting the Shurflo

Shurflo 4008 & 4048 each have two separate adjustments that need to be "coordinated". Screwdriver adjustment for internal mechanical spring bypass valve and screwdriver adjustment for pump pressure switch the turns on & off motor. If spring is set too low it will bypass too easily and pressure will not build causing pump to not shut off.

These pumps were designed to operate without an accumulator, but we later decided to add the small plastic Shurflo accumulator to extend pump off time.

We are now using the 4008 as we found the 4048 would build faster and shut off more often. We never use city water pressure, so our showers and other faucets are only pump driven.

Re: Fresh Water Pump

Reply #30 –
I will have to check out my pump model and check out the accumulator while there. I think the pump is an older model.  Not sure.
John M.

Re: Fresh Water Pump

Reply #31 –
So I checked the pressure at the tank while under pressure an it was 22 pounds.  I shut the pump and relieved the pressure at the tank still shows 22 pounds.  It seems I have the Flojet 4325-143 washdown pump.  I download the manual and it says that I don't need to run an accumulator tank.  I closed a ball valve at the accumulator and the pump.  When I open a faucet pump comes on instantly but then pulses.  Maximum pressure on this pump is 40 psi.  I don't know what the cut in pressure is.  Should I increase the tank pressure to 30 psi or just below the 40 psi?  I'm thinking I should change the pump.

Re: Fresh Water Pump

Reply #32 –
Call Flojet and ask them what the CUT-IN PSI is for that pump.  Set accumulator for that pressure less 2 PSI.  Let us know how it works.

Re: Fresh Water Pump

Reply #33 –
FloJet got back to and emailed the info.  The tank was at 22 psi when I checked.  FloJet says it should be at 24 psi.  I don't think 2 lbs. Should make that much difference.  Trying to search for any blockages in the system.  Cleaned out the screen filter at the pump and all of the faucets.  Pump still pulsating. 

Troubleshooting guide states:
Pulsating Flow -  Pump cycles on and off • Restricted pump delivery. Check discharge lines, fittings and valves for clogging or undersizing.

Is there any filter on the system water manifold?  Looking there next. Searching for blockages.  I normally run on pump all of the time.  Going to connect the city water.  If I have good flow then I will assume no blockage anywhere and the problem is the pump.
John M.

04325143A  MPU 12VDC 4.3 GPM, WD, 40PSI

o  Off Press:            40-PSI

o  On Press:            27-PSI

o  Tank Press:        24-PSI

Re: Fresh Water Pump

Reply #34 –
Easy to test the accumulator:

Shore water off.

Pump on.

Run until pump runs and then shuts off.

Turn off pump.

Open faucet-- what you get out will be 100% accumulator provided.

Re: Fresh Water Pump

Reply #35 –
Tested the accumulator and still pulsating. I disconnected the line coming off of the pump at the bottom of manifold, turned on the pump and no pulsating.  Good flow.  Thinking blockage could be in the manifold.  Anyone take one apart? Or do you replace it?  Looks like it comes apart from what I see.  Any ideas to a resolution?
John M.

Re: Fresh Water Pump

Reply #36 –
Try just closing and reopening each valve in the water manifold-- it could break loose a clog.  Not likely, but a 5 minute job.  I would have a faucet open with faucet screen removed and draining into a pan so you can see if any mineral deposits or other debris comes out.

Re: Fresh Water Pump

Reply #37 –
Well here is what I got. I removed all of the screens on all the faucets and they all had grit.  I closed all the valves on the outside manifold. Starting with the bathroom sink I played with one side at a time.  With Carmen on walkie talkie on the inside and me on the outside I had her open the cold side of the faucet to flush while I was working the valve on the outside.  A little bit of garbage came out.  We did the hot side and got a lot of grit.  Did it 3 times and still more grit.  I shut off all the faucets hot and cold on the manifold and then I went outside and I opened the hot water drain valve.  It comes off the bottom of the manifold.  I put a pan under the drain underneath the coach and got a ton of grit.  See picture attached.  Did that about 4 times and each time it was a lot.  My assumption it may be coming out of the agua hot.  I don't really know.  Any ideas?
John M

Re: Fresh Water Pump

Reply #38 –
John, hopefully it's not a manabloc problem but don't take the manabloc apart.  I had a problem with mine a while ago (it had a crack) and thought I might be able to replace the bad part.  The factory told me parts are not replaceable and that I couldn't reassemble it with correct tension in the bolts.  Of course I could if I had the specs and a jig to hold it but didn't try.  Maybe others have been successful.

Re: Fresh Water Pump

Reply #39 –
John, the Aqua Hot is just a coil of copper tubing for the hot water. Not a tank. I guess it could collect at the bottom of the loops, but it is copper and wouldn't have scale from that point.