Can I Run Suburban Water Heater Empty?

[jclark50]

I have a Suburban SW6DE water heater. I just replaced the heating element tonight and am happy that it is working. The heater had a sticker to not turn on the element until there is water in the tank. Makes sense to not burn up the element.

Strange question, but the stuff I worry about...If I’m running off my fresh water tank and run it empty, can I also accidentally fully empty my water heater tank or will the lack of pressure ensure the water heater tank stays full? I’m guessing the latter, but wanted expert opinions.

[BehindBars]

The latter is correct. When the water pump starts sucking air from the empty fresh water tank, you won't get any more water out of the water heater tank through the faucets. At that point you should turn off the water pump so it doesn't continue to run dry.

[Reverse_snowbird]

Originally Posted by BehindBars

At that point you should turn off the water pump so it doesn't continue to run dry.

I agree, but....It also depends on the water pump. We thought we'd 'broken' our water pump til we read the directions and found out that it has an automatic shutoff. When we filled the fresh water tank, the pump started working again.

[bubbles]

Originally Posted by Reverse_snowbird

I agree, but....It also depends on the water pump. We thought we'd 'broken' our water pump til we read the directions and found out that it has an automatic shutoff. When we filled the fresh water tank, the pump started working again.

Every RV water pump has an automatic shutoff but it is on the output side (system pressurized). If yours has a sensor that will also shut it off when the holding tank is empty please post the water pump type. Most unusual and first post I've read of this type of pump. Maybe I have just missed the posts.

[BehindBars]

Originally Posted by Reverse_snowbird

I agree, but....It also depends on the water pump. We thought we'd 'broken' our water pump til we read the directions and found out that it has an automatic shutoff. When we filled the fresh water tank, the pump started working again.

That is interesting. What brand and model pump do you have?

[5picker]

Originally Posted by Reverse_snowbird

I agree, but....It also depends on the water pump. We thought we'd 'broken' our water pump til we read the directions and found out that it has an automatic shutoff. When we filled the fresh water tank, the pump started working again.

Originally Posted by BehindBars

That is interesting. What brand and model pump do you have?

Very interesting and something I've never heard of.

Again, please let us know the make/model of this pump with an automatic sensor on the input side that shuts off the pump for lack of intake water.

To the OP... the advice given is good.
The only time you'd deplete the water in the the water heater with no fresh water left in the tank is if you opened the low point drains.... and... it is advised NOT to even do that unless you put the water heater into bypass so you don't suck any minerals/debris from the bottom of the water heater in the process.

[Larry-NC]

Originally Posted by Reverse_snowbird

I agree, but....It also depends on the water pump. We thought we'd 'broken' our water pump til we read the directions and found out that it has an automatic shutoff. When we filled the fresh water tank, the pump started working again.

That's very unusual. How would it ever prime itself?

Once you run the tank dry, you could never get water again, right?

[dmctlc]

Originally Posted by Larry-NC

That's very unusual. How would it ever prime itself?

Once you run the tank dry, you could never get water again, right?

Perhaps its self priming. I know Shurflo and Seaflo makes one for RVs so I'm sure there's others out there.

[BehindBars]

Originally Posted by dmctlc

Perhaps its self priming. I know Shurflo and Seaflo makes one for RVs so I'm sure there's others out there.

Can you provide an example of a pump brand and model that works as described in post #3, that automatically shuts off when the intake water supply is gone, and is also self priming when water supply is restored?

[Reverse_snowbird]

Our vehicle is in storage right now as is all the documentation for the rig.

[Larry-NC]

Originally Posted by dmctlc

Perhaps its self priming. I know Shurflo and Seaflo makes one for RVs so I'm sure there's others out there.

Obviously you responded without reading the complete thread.

The post I was responding to asserted that there were pumps that automatically shut off when the tank was empty. Such a pump could never be self-priming. It would shut off and never turn on again.

My point was to prove that there could never be a pump that automatically shut off when the tank was dry.

[dmctlc]

Originally Posted by Larry-NC

Obviously you responded without reading the complete thread.

The post I was responding to asserted that there were pumps that automatically shut off when the tank was empty. Such a pump could never be self-priming. It would shut off and never turn on again.

My point was to prove that there could never be a pump that automatically shut off when the tank was dry.

Don't make assumptions, actually I did read the entire thread but misunderstood that if it ran dry and shut off then when water was added it would start to work again. I do know it's been asked several times what pumps have this auto off & on feature since I've never heard of it in an RV before but have not seen that answered yet. The only way I know a water pump would shut off is to eliminate the demand or shut the pump itself off. As for self-priming there's SHURFLO 4008-101-E65 RV Water Pump that has built-in check valve, self-priming ability and internal bypass low cycling. There's also the Flojet 03526-144A RV Water Pump to name just a couple though I'm not sure they have what is referred to as "auto-shut off" but once water is introduced back in the tank and the demand is there these pumps "should" self-prime. Thanks and