Draining hot water tank fully?

[Double J]

So I drained the hot water tank on my 2009 cloud, but just wanted to make sure all the water is out. I pulled the outside plug and let all the water out as well as all the other low point drains on the trailer. I also blew out the fresh water lines with an air compressor.

Is there anything else needed to be sure the hot water tank is fully drained?

Thank you!

[aftermath]

It doesn't have to be totally empty. Water causes damage when it freezes and expands. With the tank almost empty any small amt of water left will have plenty of room to expand. No damage, no worries.

[ITSNO60]

The way I understand is that the water heaters with electric elements don't drain all the way, this is to keep the element submerged and protect it should it be energized before the tank is full. That said, when I did what was probably the first flush on my 10 year old unit I did multiple flushes then hooked a piece of plastic tubing to a shop vac and stuck it in the drain hole pulling out the rest of the water and a surprising amount of white bits of calcium. If you do this make extra sure it doesn't get energized before filling by turning off the circuit breaker.

[Daquenzer]

Originally Posted by aftermath

It doesn't have to be totally empty. Water causes damage when it freezes and expands. With the tank almost empty any small amt of water left will have plenty of room to expand. No damage, no worries.

Agree. No need to have the water completely out of the water heater. The only thing one really may need to do is flush it out good with a wand to get any sediments out.

[thewarden]

Originally Posted by Daquenzer

Agree. No need to have the water completely out of the water heater. The only thing one really may need to do is flush it out good with a wand to get any sediments out.

Yes, this.

[drbrick]

Just a reminder - NO antifreeze in Hot Water Tank nor the Fresh Water Tank

[uncle_bob]

Hi

If you do not pull the drain plug in the bottom of the water heater, you can have freeze damage. I know folks who have had this happen to them.

Bob

[telcoman]

i always go for a drive with the plug out and drain open. that gets rid of it and evaporation does the rest

[Dennis C]

You can use your air compressor to pressurize the lines and remove the water heater drain plug to blow out the rest of the water if you choose. When I do this, I unplug the electronic connector to the water heater to ensure that I don’t accidentally burn out my heater element in an empty tank.

[richard5933]

The Atwood manual spells out how the little water remaining in the bottom of the water heater won't cause any problems with freezing due to the shape/orientation of the tank. It's a cylinder laying on its side, and the curved shape of the bottom of the tank mean that the water remaining there cannot create any pressure as it freezes. No pressure, no problems.

[cazual6]

Originally Posted by telcoman

i always go for a drive with the plug out and drain open. that gets rid of it and evaporation does the rest

I was going to suggest that. I don't have to winterize, but from research, it was best to open all valves to prevent any possible pressure build-up from either liquid or air.

[GCinSC2]

Originally Posted by richard5933

The Atwood manual spells out how the little water remaining in the bottom of the water heater won't cause any problems with freezing due to the shape/orientation of the tank. It's a cylinder laying on its side, and the curved shape of the bottom of the tank mean that the water remaining there cannot create any pressure as it freezes. No pressure, no problems.

Richard's giving good info but here's the rest of the story this is from the Atwood service manual, the last sentence in point 4 covers the remaining water.

"3. After draining the tank, because of the placement of the drain plug, approximately two quarts of water will remain in the tank. This water contains most of the harmful corrosive particles. To remove these harmful corrosive particles flush the tank with either air or water. Whether using air or water pressure, it may be applied through the inlet or outlet on the rear of the tank or the pressure temperature relief valve. (If using the pressure temperature relief valve the support flange must be removed). The pressure will force out the remaining water and the corrosive particles. If you use water pressure, pump fresh water into the tank with the assistance of the on-board pump or use external water for 90 seconds to allow the fresh water to agitate the stagnant water on the bottom of the tank and force deposits through the drain opening. Continue repeating adding water and draining until the particles have been cleared from the water remaining in the tank.
4. Replace the drain plug and close the pressure temperature relief valve. The approximately two quarts of water remaining in the tank after draining
will not cause damage to the tank should freezing occur."

Gary

[ROBERT CROSS]

Originally Posted by GCinSC2

Richard's giving good info but here's the rest of the story this is from the Atwood service manual, the last sentence in point 4 covers the remaining water.

"3. After draining the tank, because of the placement of the drain plug, approximately two quarts of water will remain in the tank. This water contains most of the harmful corrosive particles. To remove these harmful corrosive particles flush the tank with either air or water. Whether using air or water pressure, it may be applied through the inlet or outlet on the rear of the tank or the pressure temperature relief valve. (If using the pressure temperature relief valve the support flange must be removed). The pressure will force out the remaining water and the corrosive particles. If you use water pressure, pump fresh water into the tank with the assistance of the on-board pump or use external water for 90 seconds to allow the fresh water to agitate the stagnant water on the bottom of the tank and force deposits through the drain opening. Continue repeating adding water and draining until the particles have been cleared from the water remaining in the tank.
4. Replace the drain plug and close the pressure temperature relief valve. The approximately two quarts of water remaining in the tank after draining
will not cause damage to the tank should freezing occur."

Gary

I use air thru the pressure relief valve with my MacGyver'd blaster adaptor.

Bob
🇺🇸

[Double J]

Originally Posted by GCinSC2

Richard's giving good info but here's the rest of the story this is from the Atwood service manual, the last sentence in point 4 covers the remaining water.

"3. After draining the tank, because of the placement of the drain plug, approximately two quarts of water will remain in the tank. This water contains most of the harmful corrosive particles. To remove these harmful corrosive particles flush the tank with either air or water. Whether using air or water pressure, it may be applied through the inlet or outlet on the rear of the tank or the pressure temperature relief valve. (If using the pressure temperature relief valve the support flange must be removed). The pressure will force out the remaining water and the corrosive particles. If you use water pressure, pump fresh water into the tank with the assistance of the on-board pump or use external water for 90 seconds to allow the fresh water to agitate the stagnant water on the bottom of the tank and force deposits through the drain opening. Continue repeating adding water and draining until the particles have been cleared from the water remaining in the tank.
4. Replace the drain plug and close the pressure temperature relief valve. The approximately two quarts of water remaining in the tank after draining
will not cause damage to the tank should freezing occur."

Gary

Thanks all! I feel better about the remaining water left in the tank now.
Also, good to know about needing to flush the tank out as I didn’t do that. I will need to remember to do that when I de-winterize in the spring.

Thanks again!

[Ky76Argosy]

Good info. Remember to raise opposite side tires to increase discharge from WH drain plug.

[BillTex]

Open the pressure relief valve also. I leave the plug off for the winter…just in case.

[sheriff1]

Originally Posted by BillTex

Open the pressure relief valve also. I leave the plug off for the winter…just in case.

I put the plug back in to keep out the critters.

[BillTex]

Originally Posted by sheriff1

I put the plug back in to keep out the critters.

32 years…no critters. Maybe I’m doing something wrong?