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Acampingwewillg's avatar
Acampingwewillg
Explorer II
Nov 11, 2015

Moved water pump...now it's acting strange!

OK....I have the Shur-flo variable speed 5.7 pump, have had it for many year's now. The location of the pump was in such a confined space(under the vanity sink and it has leaked before making repairs difficult. So after putting a new sub floor down, I decided to move the pump so that I can watch it more carefully and quickly make repairs(fix leaks). So I added about 6-7' of hose, turn it on and bled out the air. It all goes well until the pump shuts down, I can watch the water start to flow backwards and the pump will start back up but will not pick back up the prime(it sounds like its just spinning dry). I can turn a faucet back on and it will start pumping again.

I didn't have this issue before moving it...my only thought now is maybe adding a "check valve " in line close to the pump in-let? They do have a built in check valve, correct? I think I do recall that this particular pump may have had some issues with the strainer basket prior to entering the pump...anyone recall that problem? Anyways...open for idea's or suggestions?

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  • WyoTraveler's avatar
    WyoTraveler
    Explorer
    Nov 12, 2015
    Is the pump at the same vertical height as it was before? Some pumps have pressue to push water at high pressure but not enough suction to draw water up into it. Lookng at large scale pumps like well pumps. They can draw water from deep wells of hundreds of feet and push out under pressure but other large pumps like ditch pumps can only raise water a very few feet but can push it out under high pressure. Since most pumps I have seen in RVs seem to be mounted almost level with the bottom of the tank I suspect they can push water out with pressure but limited to how far they can raise water into the inlet of the pump. Seems to me if you just added extra water line and didn't raise the pump vertically it should operate the same providing there are no leaks in the fittings or water line
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Nov 12, 2015
    Acampingwewillgo wrote:
    Anyways...open for idea's or suggestions?


    Yes, your pump does have a check valve in the head and it should not have any difficulty priming and maintaining that prime with just 6' of extra hose on the input side. The fact you are having this problem suggests the connection(s) may be leaking and if so could be solved by using hoses with factory assembled 1/2" NPT fittings, an example being those offered in this SHURFlo Pump Silencer Kit ... each hose is 3' long and the two can be barreled together to make up a 6' length.

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