Shurflo Water Pump Running Not Pumping

[bella_intl]

Situation: 2017 International 27FBQ, the pump worked in the morning when dewinterizing and pumping fresh water through all of the lines. Later that same day on the road, the pump ran but no water was being pumped through the lines. Made sure the input side connection is good and tight, no leaks anywhere, the water heater is full, no air in the lines. When using the city water hook-up everything works properly. Looked at the thread regarding the Shurflo pump. I see that this may be a fairly common problem when the pump goes bad, bad diaphragm or bad pressure switch. Just wanted to check with the community to see if anyone has any ideas other than replacing the pump.

[Bill M.]

My experience indicates either a intake air leak or a bad pump. Have replaced 4 pumps in 2 trailers in the last 10 years. Can you see tht water intake line for the pump to see if it is full? Does the pump run but not cut off or provide water?

If the pump is not running it is the pump or a switch or the wiring. So check if getting voltage at the pump. If the pumps runs then check the intake line for air, water or bubbles.

[bella_intl]

The pump runs and sounds as it normally did but does not push any water to any of the faucets, etc. I do not see that any water is in the intake line coming to the pump. Is the pump supposed to be self-priming? Is it supposed to create enough vacuum to pull water from the fresh water tank? The intake line is clear plastic as far back as I can see it, about 18" then disappears into areas I cannot see. One thought I had was that the pump had lost its prime but I do not see how one would prime the pump.

[A W Warn]

The water pump is self priming, so nothing to do there. A SurFlo pump loosing it prime is the same thing as sucking air, weather it is through a loose connection or a pipe fitting cross threaded or a cracked strainer housing. (I've experienced all of these).

Is there a crack in the pump head? (I've had this one time after de-winterizing)

Is there a winterizing valve that might be turned the wrong way, which would make the pump try to suck antifreeze instead of water from the tank? (I've done this)

Is there water in the tank?

If the diaphragm gets a hole in it, city water overfill the fresh water tank, because it will backflow through the pump.

[waninae39]

air in the line?
clogged filter?
leak upstream?

[CBWELL]

Did you open one of the kitchen or bath taps when you turned the pump on? If everything is shut off, and only air in the lines, you won't pick up any water from the tank!!

[bella_intl]

Appreciate everyone's input. There is water in the fresh water tank, about 50%. Since I'm normally using city water presently there is pressure in the lines. When I turn off the city water and turn on the pump water flows from the taps (kitchen for example) for a few seconds but then trickles down to nothing with the pump motor running. I am out of the trailer for the rest of the day but will try a test later today. There is no winterizing change-over valve. One must disconnect the intake line from the fresh water tank and connect a long tube to the intake side of the pump that is then placed in an antifreeze bottle. I'm going to connect that tube and see if it will suck water from a bucket of water. If it does, then I know air is getting into the intake side of the pump when connected to the line that runs to the fresh water tank.

[Isuzusweet]

If the pump inlet hose is somehow at any point above the level of water in the tank, the pump will not be able to pull the water up the pipe.
I have to make sure to push my inlet hose below the level of water in my tank, the first time I fill and turn on the pump.

Cheers
Sidekick Tony

[jcanavera]

I fought a battle with my pump only to find that the filter was clogged with a very fine coating of sediment. At first glance the filter looked good but I removed it from the pump and inserted a large nail to scrape the filter. I scraped a small portion, put the filter back on and the pump was able to pass water through it. At that point I bought a replacement filter and all has been fine ever since. Just be aware it doesn't cause much sediment to clog that screen in the filter, and just on looks alone it may not look like an issue. Personally I'd suggest as a first step to deal with water flow issues, if the pump is running okay then change the filter. See if that makes a difference.

Jack

[OTRA15]

Great point, Jack.

Peter

[wave man]

Great thread, having this issue just now so my thanks to all

[GCinSC2]

Just an FYI on technique for testing pump and easy power supply.

https://www.youtube.com/watch?v=jV48CSBl_4Q&t=4s

And IF you need to have pump out and use water system look at the swivel discharge end of pump. Take the same size plastic plug that you have on hot water tank and cap it off. 1/2" plastic plug. Good thing to carry a spare.

[fran&frank]

I had a similar problem and it turned out to be the plastic cap on the filter just before the pump was not tight so the pump was sucking just enough air to not provide water pressure. But as said earlier in the post check to make sure all the connections before the pump are tight because they are often loosened when winterizing.-- Frank

[ttrout]

Take the pump apart to insure there is no particulate contamination in the pump. I found small pieces of plastic in mine. After cleaning worked it great.

[bella_intl]

Update on the original issue: It occurred to me that in order to see if air is getting into the line between the pump and the fresh water tank I needed to bypass that connection and get water directly into the pump. So I disconnected the intake line and connected the line used to get antifreeze into the lines. I first tried just hanging the line in a bucket of water turning on the pump and opening a faucet, pump runs but still no water flowing. Then I filled the line with water (primed the pump y'all) and it started pumping water. A lot of air was pushed out to start with then water flowed normally, both the cold side and the hot side. That suggests there was an airlock or similar condition downstream of the pump. I do not know where the city water enters the fresh water plumbing. Could there have been air between the pump and where the city water enters that created a condition that prevented the pump from operating normally?

[GCinSC2]

Did you watch the video in post 12?

Bad pump did not self prime.

New pump did self prime.

[bella_intl]

GCinSC2 - I did watch the video, he did do what I did initially, but he did not prime the pump like I did. I'm not convinced my problem is solved, will see what happens when I get home in a couple days. May need to replace the pump.