Quick emptying of fresh water tank

I discovered this trick by accident yesterday when I was draining the fresh water tank in preparation for sanitizing the water system, as well as checking the anode rod.

If you remove the anode rod and turn on the water pump, the fresh water tank will drain a lot faster through the water heater than it will through the drain on the tank itself. Not all the water will be pumped out, so you still need to open the regular drain to get that last bit out.

The accidental part was the water pump being left on while traveling home. I'm not sure how it got turned on because we were on city water where we were camped. Anyway, my first clue that the pump was on was getting sprayed when I removed the anode rod. Then, it seemed like a lot more than 6 gallons was draining through the hole. When I refilled the tank with Clorox water, the flow meter on my hose confirmed that I put close to 30 gallons in, so it must have been drained pretty well.

I was told on FB when I posted this that the newer pumps are designed to be safely run dry, which was definitely a concern I had.

I haven't seen a Sure Flo pump yet or in years that didn't run dry, meaning it doesn't hurt it. I put a valve versus a cap on my freshwater tank, not sure I'd want to pump 30 gals thru the water heater outlet.

Originally posted by mcarter I haven't seen a Sure Flo pump yet or in years that didn't run dry, meaning it doesn't hurt it. I put a valve versus a cap on my freshwater tank, not sure I'd want to pump 30 gals thru the water heater outlet.

What's the diameter on the orifice for your drain? Is it considerably larger than the one on the factory drain?

Originally posted by StephenH OTOH, it is one way of flushing out the water heater.

Good point. It would get all that grit out.

My drain valve is 1/2" pipe thread. So NO, it is the same size as the drain. I also disagree that draining thru the water here, necessarily flushes it. I flush with high pressure wand to clean my water heater, your pump probably supplies 3 GPM out the anode hole, it will empty fast, but a hole that big will not allow a lot of pressure.