pumps ruined when water line shut off - how long does this take?

[smithfield]

Apparently the water pipe to the pool and spa were accidentally shut off sometime in the last week or two. This ruined both pumps and they need to be replaced.

My question is how long does it take to ruin a pump without water? Our pool service person comes twice a week. Should they have noticed? Or could it happen quickly without warning?

It looks like there may have been a small leak in the line, which created a puddle and a passerby or landscape person turned the valve off. We don't know when.

Even in Phoenix where water evaporates very quickly, wouldn't this have taken more than a week or two?

Is there a way to prevent this from happening in the future, with an auto shutoff or something?

Thank you,

 

[jblizzle]

Welcome to TFP!!!

If you starve the pump of water flow, it could overheat and be ruined in a matter of hours.

Although I am confused. Are you saying an auto-fill was turned off and the water then dropped below the skimmer? Or was a pool valve at the equipment turned off stopping the flow of water?

There are some pumps / automation that have safety features that will turn themselves off if there is not adequate flow.

 

[smithfield]

The water line to the autofill was turned off. Then the water line went below the skimmer in both the spa and the pool.

 

[racket]

I have seen pump run dry for days with no damage... I have also seen them run for hours and get completely melted down.

 

[Citizen]

I would agree along the lines of racket's post and say it is a case by case basis. There is no set timeline for a motor to be shot after it has run dry.

I have also heard the quality of shaft seal can affect how long they can run dry. For example a silicon carbide seal will allow a pump to run dry for longer because it does not build up as much heat as a standard seal. Again, that is just what I have heard and not a solid fact.