What is the best water pump to use for pressure on the fresh water system without having to use an accumulator tank.
John M.
John,we replaced ours with a Shurflo,will get the model but I talked to their customer service and there is no need for a tank,ours
works fine.
We also went with SureFlo. AquaJet is also a good choice.
SureFlo (https://www.amazon.com/gp/product/B007RYMT7O/ref=oh_aui_search_asin_title?ie=UTF8&psc=1)
jor
Shurflo 4008 or 4048
Water Delivery | RV (http://www.pentair.com/en/applications/enjoying-water/rv/water-delivery.html)
Just replaced mine with a new Remco Aquajet 5.3 GPM unit.
Why would you not want an accumulator tank?? They really do save a lot of cycles on the pump, and that is what wears out a pump sooner than necessary. I put a larger than original in our coach and it really cuts a lot of wear and tear off of the pump. Have a great day ---- Fritz
We have a sure flow with no tank but I ordered a tank to add on (haven't done it yet) to avoid the surging of the pump on low flow. I don't like the system with no tank.
Reply to reply #5,less fittings,less leaks.
We have the Shurflo 4008 and later added a small black plastic Shurflo accumulator with a couple of flexible hose connections. Pump and accumulator is not fastened down. Seemed that a small accumulator helps, but is not required.
Agree 100% with Barry. I installed a new 4008 pump, and removed the blue pressure tank. Tried it for a while, but not happy with the way pump had to run every time, the instant a water faucet was opened. Reinstalled the blue tank - now much happier. The pump works fine either way, but operation seems to be much more "relaxed" working in tandem with a pressure tank. Just a subjective opinion, of course.
One other thought about pressure tanks. They may provide a secondary function of damping the pressure fluctuations in the hot water tank caused by the heating cycle. I have seen reports of RV owners having a problem with hot water dribbling out of the pressure relief valve on the water heater. Seems this can happen when the water heater is 100% full and there is no "air gap" in the tank. With a pressure tank, you probably don't need to worry about maintaining the air gap in your water heater. One less thing to keep you from kicking back and enjoying a cold one!
Go to the link below, and read down to the bottom of the very helpful article, where "air gap" is explained:
RV Water Heater Troubleshooting - Simple Maintenance Will Save You Money! - (https://yourfulltimervliving.com/rv-resources/rv-water-heater-troubleshooting-simple-maintenance-will-save-you-money)
May be a good idea to have a spare relief valve handy,they are not made to be opened and closed alot and may not reseal.
But, they can be found in most hardware stores. Not sure they would make my "top 100 parts" list.
I installed the new style Surflo. Added the tank back (PO took it out) Granted the pump ran less, but when it ran, it ran longer then just the short squirts when flushing.
Took the tank back out.Works way better IMHO.
Home depot sells the tank with no mounts $39.00. I have one if someone needs one.
Chris
When I went hunting for a replacement valve, the local "usual suspect" big box stores did not stock a valve with 1/2" pipe thread. Seems most residential hot water heaters use a larger thread size. Having one on hand in a emergency situation
may save you some time...or not...depending on local inventories.
0121325 - Watts 0121325 - 1/2" LF1XL-4 T&P Relief Valve, Lead Free (150 psi) (https://www.supplyhouse.com/Watts-0121325-1-2-LF1XL-4-TP-Relief-Valve-Lead-Free-150-psi)
I'm currently running a tank with my pump but I'm not happy with the pressure I get when opening the faucets. Also pressure gets very low before pump kicks in. I'll have to check the tank air pressure and make sure it's not leaking. Everyone thanks for the input. Maybe I'll keep the tank and upgrade the pump. To be continued.
John M.
Short cycling electric motors can build heat in the windings with inadequate run time. I replaced my accumulator tank because the bladder had a leak and it was waterlogged and not accumulating. As for the water heater the check valve on my constant speed pump won't allow for thermal expansion when the water heater starts up cold if the accumulator is waterlogged or way too small, and hopefully leaks out the relief valve. Variable speed pumps may not need or have a check valve as there is no accumulator (but my guess is it has one). Said another way if there no check valve on a variable speed pump with an accumulator the pump motor could be made to spin backwards as the accumulator now starts to push the water back to the fresh water tank and really pull inrush amps if it's still coasting backwards. You paid to pressure up the system. I kinda prefer the simple constant speed stupid pump/accumulator for these reasons. Just my 2 cents. Spare relief valve may make a trip more pleasant if it fails due to a check valve, waterlogged accumulator, closed inlet valve. And never exercise the relief valve as prudent, on a trip or if you don't have a spare valve. Cause when exercised they typically fail open. Most home or building inspectors won't touch releif valves for this reason.
We use a small plastic Shurflo accumulator, bigger may not be as good. Also we buy Atwood part Temp-Press release valve. Pump worked ok without accumulator.
Shurflo 4048 & 4008 are NOT variable speed. They do their low flow control feature with a spring loaded internal bypass that flows out back to in. We also plumbed Temp-Press valve to outside of compartment through the floor hole that the hot/cold/fresh dumping goes to the ground.at the hot/cold/fresh dumping goes to the ground.
Barry that makes sense tiny accumulator to help dampen pump pressure pulses and absorb the expansion from the water heater would be a very desireable feature. Bypass would allow tighter control pressure regulation. Obviously it has a check valve on the inlet. Mistook varible output flow via bypass, as variable rpm.
Available from Amazon for a better price than the link I posted above (Reply #14).
Amazon.com: Atwood 91604 1/2" Relief Valve: Automotive (https://www.amazon.com/Atwood-91604-Relief-Valve/dp/B000N9PRKG)
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.
Thanks Brett! Will check the tank.
John M.
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.
Yup, a homemade accumulator.
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
2 gallon accumulator should be no problem.
Have you had a chance to check the accumulator PSI?
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.
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: 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.
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.
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.
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.
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
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.
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.
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.
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
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.
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.
Scale forms on heat exchangers at the hottest spot, if the aquahot has a spiral coil you can sometimes shock the scale off by cycling between full hot and full cold as the extreme expansion by the copper coil tends to break the scale off. Velocity is your friend when it comes to cleaning out pipe debris or scale, the more the better. Connect to elevated city pressure water, remove faucet airaters open all faucet valves, then open valves individually whether hot or cold and let it run a minute. Repeat as necessary to maintain maximum velocity in each pipe system, and the common maniblock with everything full on. Pump is to tiny to flush.
Only the hot water goes around the coolant tank, no flame involved. I have seen posts on using vinegar to clean out the hot water lines on Aqua Hot systems.
Flame or not scale forms, vinegar is a good yearly treatment.
Replaced my leaking Sureflow with a new one
Brand: SHURFLO
4.6 out of 5 stars 3,504 Reviews
Shurflo 2088-554-144 Fresh Water Pump, 12 Volts, 3.5 Gallons Per Minute, 45 Psi
After a day or two of normal ops, it seemed to develope some sort of hydraulic lock and no flow, pump not running...bled the air precharge off the accumulator, and now ops normal...previous pump no back flow check valve, this new pump has one,
Any ideas? Ditch the accumulator?
I like having the accumulator tank which works fine with my pump. I would ditch the check valve or pump were it my choice. All the best making your decision.