Water pump runs when the water runs out

[Bruce and Jenna]

This week we have been using our fresh water tank. And have noticed that the water pump does not shut off when the tank runs dry. We have the upgraded Shurflo variable speed pump and whole house water filter.

Is this right? Surely the pump would burn out eventually if we didn't notice and didn't turn off the switch.

[Bruce and Jenna]

This week we have been using our fresh water tank. And have noticed that the water pump does not shut off when the tank runs dry. We have the upgraded Shurflo variable speed pump and whole house water filter.

Is this right? Surely the pump would burn out eventually if we didn't notice and didn't turn off the switch.

[Roger Watts]

No, I believe this is the way they all function. I'm sure the pump was designed by Tetford/Norcold engineering dept.
Thankk God they don't work on the space shuttle!!

[Max1]

Bruce...
Our variable speed pump will keep running if there is no water and I was told it won't hurt it to run dry by more than one rv tech. That said though on Shrflo web site some pumps state they can run dry and others say nothing. I would be interested to here more on this???

[rockintom]

All I can say is we have run low on fresh water on our Shurflo 5.7 and I quickly got to the switch to shut it off while I put in more water. This thing makes some nasty noises when running dry that I don't like. After FTing for 3 years, I can come real close to guessing how long I can run this thing before sucking air when the fresh water low level light on the monitor goes out!

[Max1]

We to have the 5.7 Shurflo so I did some more research and found in the Data Sheet that it does state "Run Dry/Yes". That said I wouldn't let it run dry any longer than necessary but it should not hurt for short period's.

[D and J]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by rockintom:
This thing makes some nasty noises when running dry that I don't like. </div></BLOCKQUOTE>

Oh, baby, I can atest to this!! We ran our tank out for the first time today (just outside of Big Bend National Park)

I never want to hear that noise again!

[rockintom]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by D and J:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by rockintom:
This thing makes some nasty noises when running dry that I don't like. </div></BLOCKQUOTE>

Oh, baby, I can atest to this!! We ran our tank out for the first time today (just outside of Big Bend National Park)

I never want to hear that noise again! </div></BLOCKQUOTE>

Sounds detrimental....don't it?

[John66]

The pumps run when the pressure drops below the specified amount. With air in the system, the pressure cannot be maintained, so the pump will run.

[Bounder94]

You should tear into on of those pumps sometime to see how they work...when you do, you'll see how it will NOT hurt these pumps to run dry....I helped a guy replace his diaphram and valve plate...they are very interesting how they work, definitely hard to explain, but then you'll see that there is nothing to "burn up" when they run dry....seems like a good deal to me.....

Kelly