Completely closing valves downstream of a pump

When I do water changes I completely close the valve downstream of my return pump, to prevent it from running dry and blowing bubbles into my display tank. Will this technique damage my pump? Thanks!

 

Why not just turn off the pump?

 

I have the plug in, in an inconvenient place.

 

it wont hurt the pump contrary to popular belief. if you think about what is actually happening inside the pump it all makes sense

 

Short term it will not hurt anything, it is what is called Dead Heading in the pump industry. Long term it creates heat which could cause problems so I would keep the down times to a minimum.

 

Yeah I would rather dead head it then run it dry at least there will be plenty of water to cool and lubricate the pump.

 

Thats not the case though. The water in the pump is static or not moving while the impeller keeps spinning which creates heat and eventually steam if left long enough. You don't want to let it go that long, thats what ruins pumps.

 

Yeah but running dry would create more heat. What I was saying is merely if he had to leave the pump on, closing the valve for a few minutes wouldn't be as bad. Of course I work with much larger pumps 200HP where anything out of the normal operation is bad but I have run my return with the valve closed off for like 10min no problem (i forgot I closed the valve)

 

All in all, the best thing would to turn it off, either wire a switch inline if it is hard to unplug it Or relocate where you plug it in. I have all my pumps on a single power strip and I simply turn the power strip off during maintenance makes easy work.

 

Ya, I would put the pump on an outlet strip mounted somewhere easy to get at. I have all my pumps on a few different outlet strips on different electrical circuits so if I lose one GFCI chances are another will still be running. Another level of redundancy.