Update on Shurflo 5.7 Smart Sensor pump

[dgerstel]

There has been many posts on problems with the Shurflo 5.7 Smart Sensor pump. I am not sure if everyone has cured their problems or not, so I thought I would update my experience with the forum.

On my last post about my pump, I had installed the ShurFlo Aqua King™ Premium 4.0, a combo unit of standard pump and accumulator together, supplied by Shurflo. I had increased the pressure setting about 5-10 PSI, to facilitate coach cleaning with a pressure nozzle on the hose. I had found that the standard pump (set off/on point) allowed for an unpleasant variance in water flow. On this trip, the pump started to blow the 20 amp fuse and was cycling on and off before it reached top pressure cutoff. I found that it was not shutting off until about 95 PSI and the adjustment was no longer working right. I just re-installed the last 5.7 Smart Sensor pump that I had, leaving the Shurflo accumulator tank installed. I find that this combination works very well for me. The tank handles any low flow cycling problems and the Smart Sensor pump turns on when the tank pressure drops a bit and then stays on for long use, like for showers.

My recommendation for anyone, that can not get a 5.7 Smart Sensor pump to work right, add an accumulator tank. Shurflo will say that it is not required, but their personnel from engineering and service have told me that it is OK to do.

[dgerstel]

There has been many posts on problems with the Shurflo 5.7 Smart Sensor pump. I am not sure if everyone has cured their problems or not, so I thought I would update my experience with the forum.

On my last post about my pump, I had installed the ShurFlo Aqua King™ Premium 4.0, a combo unit of standard pump and accumulator together, supplied by Shurflo. I had increased the pressure setting about 5-10 PSI, to facilitate coach cleaning with a pressure nozzle on the hose. I had found that the standard pump (set off/on point) allowed for an unpleasant variance in water flow. On this trip, the pump started to blow the 20 amp fuse and was cycling on and off before it reached top pressure cutoff. I found that it was not shutting off until about 95 PSI and the adjustment was no longer working right. I just re-installed the last 5.7 Smart Sensor pump that I had, leaving the Shurflo accumulator tank installed. I find that this combination works very well for me. The tank handles any low flow cycling problems and the Smart Sensor pump turns on when the tank pressure drops a bit and then stays on for long use, like for showers.

My recommendation for anyone, that can not get a 5.7 Smart Sensor pump to work right, add an accumulator tank. Shurflo will say that it is not required, but their personnel from engineering and service have told me that it is OK to do.

[rbguinn]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Shurflo 5.7 Smart Sensor pump </div></BLOCKQUOTE>

We are relatively new RVers. Recently, during a a week long trip, I believed the Shurflo 5.7 Smart Sensor pump in our coach was going bad.

Having added a 300 gpd RO system to our coach a several months ago, we are depending on this pump to take care of all our fresh water needs from our fresh water tank and it did wonderfully for our 70 day 2008 summer adventure.

The pump was running continually without reaching the cut off pressure of 65 psi and we had low water pressure in the coach. After ordering a new pump, I chose to go though a process of elimination to insure that the pump was indeed bad.

I identified I had the water inlet valve in the service bay set to "Fresh Tank Fill" which I set when sterlizing the fresh water tank before the week long trip. I discovered that the position of the water inlet valve makes a difference. Having the valve set to "Fresh Tank Fill" the leaking of water from one part of the system to another could be heard.

Much to my surprize, when I turned the water inlet valve to "City Water", the Shurflo pump pressurized the system to 65 psi and the pump again automaticially turned off. We are currently on a two week adventure and the pump continues to work great. I do not understand why or understand the engineering configuration of the coach fresh water system.

We have a new Shurflo pump in our basement as a Plan 'B' when our current pump truely no longer works approprately. This was an idea we had previously considered anyway.

[dgerstel]

rbguinn,

If you do a search on this pump you will find a posting from Engineer Mike about the problems with the 3 way valves WRV used. I had installed my RO system while still at the factory getting our "delivery repairs" done. I immediately found a problem with water back flowing thru one of the 3 way valves and added a check valve to eliminate it. As I have posted previously, WRV's, Shurflo's service and engineer staff and my self tried many solutions to make the pump work correctly to no avail, I just gave up and added the tank. I would have rather just used the pump as is, but adding the tank is easy, low cost and has no negative effects if you are having a problem that can't be solved. While I used a large tank, with this pump I think the small plastic one Shurflo has will probably work just fine.

[EngineerMike]

Unfortunately the cheap plastic 3-way valves are not uniformly good for 65 psi. Seems some work just fine, others leak down slowly, others like guinn's leak enough for the pump to run continuously. Fortunately, WRV placed them all in the utility bay. If you don't want to worry about the 3-way leakers forevermore, it takes 2 check valves.

I used John Guest type check's due to ease of installation & quality of operation. You need one between the hose inlet and the spin-on filters, otherwise you can get leakage back thru the filters & into city water if city water pressure is low enough and you happen to have weak OEM valves there. Then you need another after the tank fill 3-way. Basically you isolate the cheap valving by using two check's facing opposite directions. I never finished this in our 06; rather lived with it by turning off the 5.7 pump at night so I didn't have to listen to it cycle every few minutes. In the 08 I put in the easy check valve (preventing back flow thru filters) then checked for the internal leak. Sure enough the pump cycled every few minutes, so I added the second check, keeping pressure from pump out of the valves. Now it is tight as a tick. For an 08 I found it was easier to add several elbows (also JGuest type) and short lengths of 1/2" o.d. tube to make install of the second check valve easier; the OEM assemblage of valves & tubing doesn't leave much tubing between fittings to cut & splice in the check.

[VAGABONDMAN]

THE CHEAP THREE WAY VALVES WRV USED ARE "DIRECTIONAL" AND ARE NOT DESIGNED TO PREVENT BACKFLOW. I DISCUSSED THIS AD NAUSIUM WITH WRV - NO CHANGE. USING THE CHECK VALVES IS A GOOD CURE, BUT YOU CAN ALSO CHANGE OUT THE CHEAP VALVES FOR THE ONES I USE IN MY INSTALLATIONS - MADE BY SEE TECH. THEY ARE THE PUSH ON TYPE SIMILAR TO JOHN GUEST ETC. THEY ARE A POSITIVE BALL VALVE DESIGN AS OPPOSED TO THE WRV ONES THAT HAVE A RUBBER SLEVE THAT ALLOWS THE BACK FLOW.

I CAN'T TELL YOU HOW MANY ALPINES I HAVE REPLUMBED BECAUSE OF THIS!!!

[Basil Shannon]

Frank, where can we get these See Tech valves? An Internet search did not reveal much.

Our Vagabond RO system in the Apex is taking 500+ PPM water here in Palm Springs down to about 7 PPM. Still love it!!!

[VAGABONDMAN]

Basil, that's great news.

I get the seatech valves from my supplier. Home Depot handles a similar brand, but so far they havent had any three way valves. If you want some, contact me.

[rbguinn]

Thank you all for a higher level understanding of my fresh water system as it relates to a RO system and the quality of the OEM 3-way valve. Changing to a high quality 3-way valve (Fresh Water Fill / City Water) is something I will be researching (thanks for sources) and installing to replace our already new and poor quality 3-way valve in question. I previously recognized the need for at least one check valve in my design solution for installing a RO system.

My design solution for installing our RO system included drilling a new hole in the Utility Bay wall, installing a new water inlet female assembly, routing the water through a brass check valve on the back side of the new inlet, farther routing the water to a brass ball valve (which required another new hole and securing clamps, and then routing tubing directly to the RO system. The RO water output fill line was routed to a new 1/4" X 1/2" T in the line leading to the fresh water tank and is on the same line from the above 3-way valve. The waste water was routed from the RO system to a barbed brass fitting which was mounted in the bottom of the Utility bay wall. A good length of thick high quality plastic tubing is pushed on to the barbed brass fitting , which is dropped out the bottom of the bay with the electical cable and main water source hose. The end of the plastic tubing is layed into the sewer access and the system is ready to activate. I simply pull the plastic line when I need to deal with draining the black and gray water tanks. When I turn the system off with 100 gallons in our fresh water tank, the pressure in the fresh water tank does not push water in reverse through the RO system to flow out the waste water tube. So far this solution has worked great with the exception of our 3-way valve mystery. Thanks again.