I just purchased the house and I did not convert the water utility into my name in time and it was shut off. (The water will be off for 4 days as its the weekend).

The water pump on top of the water tank started making noise and was very hot to touch after 1 day without water. The service man came and shut off the tank and pump, there was no water in the tank.

Is it a leak or does water drain back from the tank when the main is off?

Please help, i am so nervous.

  • Water pumps need water to keep cool/from over heating. Pump might to be repair or fixed now. Turn off water heater also if not done already. They can be damaged also if no water/not full of water in them. Water pressure tank will be okay/no change.
    – crip659
    Apr 3 at 18:05
  • Yes, we had it turned off now. So at this point i will just test everything once the water is back on? Is there a chance of a flood? I literally know nothing about this, my first house EVER!
    – Jennifer P
    Apr 3 at 18:26
  • Where are you? it makes a difference. I don't know why you'd need a pump on top of a water tank if you are on a public water supply.But maybe if your supply is very low pressure, a pump may be needed to bring it up to usable pressure. Keep the water heater and pump turned off until you restore your water service. Keep in touch, we're here to help you! Pictures of your setup always help as well as make and model numbers of involved components. Apr 3 at 21:33
  • Im on Long Island, NY. Will keep it off until the water comes on. Hopefully the boiler and tank are fine. Thank you so much for replies!
    – Jennifer P
    Apr 3 at 22:48
  • It would be helpful to see a photo of the set-up you're talking about. Is it a gas heater with electric pump? An on-demand electric heater? A standing tank usually has the water supply and exit from the top. If the heater element was on long enough (a full day?), it might have boiled away the water. For the future, you should review your breaker box and make sure the circuits are identified. If some electrical problem occurs, turn the thing off, unplug it if you can, or flip the right breaker switch. If the pump does not have an on/off switch it is probably on a dedicated line. Apr 4 at 23:27

If you have a booster pump as it sounds the seal from the pump to the motor may have been damaged from pumping without water.

These seals are usually a very hard/brittle ceramic material that if run without water can crack and then the pump seal leaks (but is repairable).

You may have gotten lucky and things just got hot. I have had pumps deprime and get very hot and not crack the seal. I have also seen brand new pumps turned on with no water and the seal cracked in under 30 seconds.

Once you have water again turn it on and let it fill some before turning on the pump. When these seals fail it is usually a fast drip that never stops and can get worse (not good leaking water and power) if the pump doesn't leak once there is water and running at full pressure it should be fine.

  • I will take a SWAG and say the water heater uses a combustible gas and it is of a high efficiency design. The pump could very well be an exhaust venting fan.
    – Gil
    Sep 2 at 15:03
  • 1
    @gil the pump is at the water tank and a vent fan or inducer motor would not have a problem with no water. Most pumps are centrifugal style and the only contact point is the shaft seal to the motor. No fresh water the seal will heat up if there was some water still left to “lubricate” the seal it may be fine. But not a fan.
    – Ed Beal
    Sep 2 at 15:50

Is it a leak or does water drain back from the tank when the main is off?

If there was no leak before the water was shut off then there is no reason for there to be one as a result of it being shut off. (the pump overheating may(?) have caused problems to plumbing connections)

You will not be able to determine if the pump is still functioning until the water is back on and you can see it pumps water.

Is it a leak or does water drain back from the tank when the main is off?

In my experience the municipal water supply pressure is enough to keep the tank full and will not allow a back flow, but i do not know anything about your particular situation and why you have a pump on your water heater.

You also will need to determine if the water heater itself was damaged from firing up without water in it. (did the service person say anything about that?)

  • Thank you so much for reply! No, the service person said nothing about it, said we need to have the water back on to see if anything is damaged. I just read a post how the water may syphon down the cold water pipe out of the tank, but again not sure of the reason the tank was totally empty, no leak around it noted.
    – Jennifer P
    Apr 3 at 18:24
  • I would say you want to be able to inspect the pump and WH at the moment the water supply is turned back on. You will need to know where your main water shut off valve is, in-case the pump or WH leaks, so you can quickly turn it off.
    – Alaska Man
    Apr 3 at 18:47
  • @JosephFilip Perhaps you meant to post that in the comment section of the question instead my answer?
    – Alaska Man
    Apr 4 at 17:27

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