When former BF & I had a RV together, we drained the water heater ( or thought we did) by opening the low point drains and parking on a slope so that the water heater was uphill. We then winterized by closing the WH bypass & pumping pink stuff through the lines, plus pouring in traps. Never had any problem for 3 years.Now that I'm reading with an eye to doing this on my own in the future, I see comments that say things like, "Water heater drain plug must be removed to drain it."Were we just blissfully ignorant and got lucky? (Which I doubt, as RV was stored in central IL for the winter.) Or did we manage to drain the water heater through the low point drains?And what is there to prevent the WH from draining through the low point drains?

Low point drains are for Hot & Cold plumbing lines.Water heater tank drains via drain plug which is located in water heater outside compartment.Some water heaters can drain thru cold inlet int cold water lines and out cold low point drain. Depends on how plumbing is done/installed.Best to NOT count on it doing so.Best to always drain via drain plug----that way you know WH tank has been drainedBesides water heater should be drained/flushed at least once a year for routine maintenance. Winter time is a good time to do so

Yes, you were lucky!Drain the WH - it's easy to do.

I think your procedure is ok since I did the same and have never had any problems

take the chance for a 1 minute job? Pull the plug!

If your water heater is a Suburban model, it will have an anode rod that needs replacing from time to time and it is attached to the drain plug. Remove the drain plug to see how much of it is left and replace as necessary. If you have the plastic looking plug, the water heater does not have the anode rod, but should still be drained. As said, it only take a minute or so for peace of mind.

Draining water heater | Good Sam Community

coolmom42
Explorer II
Jan 19, 2015
joebedford wrote:
Mine doesn't drain through the low point drains. Are you SURE yours does? Personally, I wouldn't take the chance until I knew for sure.

This is what the plumbing in my rig looks like:

Yours is probably similar. Can you be sure all that drains just by opening the low point drains?

The plumbing in your photo is a hot mess. Good grief. Nothing in the RV I dealt with looked like that. It was very straight-forward & easy to figure out which lines went where.
Old-Biscuit
Explorer III
Jan 19, 2015
coolmom42 wrote:
As I said, I am no longer involved with this TT, having split with the now-full-owner. (He bought my half of it.)

I was just trying to figure out the best way to do it myself if I buy a RV in the future.

The TT is a basic Gulfstream Amerilite. It never occurred to us that the WH would NOT drain through the low point drains. We had the faucets open while draining. It did drain slowly but the amount of water seemed to confirm that the WH did drain.

If it was not drained, it definitely would have frozen under the storage conditions.

I believe it's an Atwood WH, am not 100% sure.

So the moral of the story is, some WH might drain through the low points, but not all will. And the anode should be checked regardless. (I don't know if ExBF has done that or not, it's not really my concern any more.)

Atwood doesn't use an anode rod because it has an aluminum alloy tank.
(Suburban uses anodes because of the steel glass-lined tank)

WH tank may have drained, may have only partially drained.......regardless it must have drained enough that the water left behind had enough room to expand when frozen that it didn't do harm ie: rupture tank

BUT easy sure fire way is to remove drain plug
doughere
Explorer
Jan 19, 2015
If yours is a Suburban you need to pull plug to check anode yearly. If it is an Attwood, you can get a MPT to Male Hose Thread adapter, and put on a Hose cap which can be removed by hand (idea stolen from somewhere on this site).

Doug
coolmom42
Explorer II
Jan 19, 2015
Old-Biscuit wrote:
coolmom42 wrote:
As I said, I am no longer involved with this TT, having split with the now-full-owner. (He bought my half of it.)

I was just trying to figure out the best way to do it myself if I buy a RV in the future.

The TT is a basic Gulfstream Amerilite. It never occurred to us that the WH would NOT drain through the low point drains. We had the faucets open while draining. It did drain slowly but the amount of water seemed to confirm that the WH did drain.

If it was not drained, it definitely would have frozen under the storage conditions.

I believe it's an Atwood WH, am not 100% sure.

So the moral of the story is, some WH might drain through the low points, but not all will. And the anode should be checked regardless. (I don't know if ExBF has done that or not, it's not really my concern any more.)

Atwood doesn't use an anode rod because it has an aluminum alloy tank.
(Suburban uses anodes because of the steel glass-lined tank)

WH tank may have drained, may have only partially drained.......regardless it must have drained enough that the water left behind had enough room to expand when frozen that it didn't do harm ie: rupture tank

BUT easy sure fire way is to remove drain plug

I agree you are right about that. Will keep it in mind when I acquire my own RV. Good to know ahead of time.
coolmom42
Explorer II
Jan 19, 2015
doughere wrote:
If yours is a Suburban you need to pull plug to check anode yearly. If it is an Attwood, you can get a MPT to Male Hose Thread adapter, and put on a Hose cap which can be removed by hand (idea stolen from somewhere on this site).

Doug

Great tip! I will keep that in mind when I acquire a RV.
wolfe10
Explorer
Jan 19, 2015
doughere wrote:
If yours is a Suburban you need to pull plug to check anode yearly. If it is an Attwood, you can get a MPT to Male Hose Thread adapter, and put on a Hose cap which can be removed by hand (idea stolen from somewhere on this site).

Doug

And, now you have introduced electrolysis to the water heater. Atwood uses a nylon drain plug for their aluminum tank.

Put one or two dissimilar metals in contact (very likely to be higher on the galvanic chart) and you have done it no good. How much damage will depend on mineral content of water and how much the water heater is used.

Bottom line, not a good idea. Spend the $1 or $2 any buy the Atwood drain plugs from any RV store.

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