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Water pump ran partially dry

Posted by Slimy_Okra (My Page) on
Mon, May 12, 14 at 1:05

OK, first of all I'm not a DIY person so please bear with me. I have a fairly new Grundfos MQ. It pumps water from my storage cistern (that receives water from the city) to a larger concrete tank I use for gardening, via a crossfeed valve. I left the valve open today and totally forgot about it. It pumps water out faster than what comes in from the city, so when the water level got down to the level of the intake, it began gurgling and pumping a mix of air and water. At this point it was pumping exactly the same rate as what was coming into the cistern (because some of it was air) so I don't know how long it was running this way. I would estimate one hour. It was not hot to the touch and it reprimed itself and seems to be running OK so far.

So my question is: should I have this pump inspected by a technician to check for damage? This pump is critical for both household and garden, so I don't want it failing on me.

This post was edited by Slimy_Okra on Mon, May 12, 14 at 1:10

Follow-Up Postings:

RE: Water pump ran partially dry

Although the pump does have run-dry protection, I would have the pump checked out. You may have had some cavitation in the pump which could have damaged the impeller or casing.

RE: Water pump ran partially dry

That set of circumstances would not cause cavitation. Running a pump with the seals dry could damage the seals. If the pump seems to be OK, it is 99% certain to be so. Find something else to worry about.

RE: Water pump ran partially dry

Given the small amount of information supplied by the OP, it could be cavitation or air ingestion on the suction side. There is no need to split hairs, however, because the average homeowner isn't going to know the difference in diagnosing the problem. Either condition will result in precisely the same potential damage to the impeller.

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