Forum Discussion

coolmom42's avatar
coolmom42
Explorer II
Jan 18, 2015

Draining water heater

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?
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Jan 18, 2015
    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 drained

    Besides water heater should be drained/flushed at least once a year for routine maintenance. Winter time is a good time to do so
  • fischer's avatar
    fischer
    Explorer
    Jan 18, 2015
    I think your procedure is ok since I did the same and have never had any problems
  • robsouth's avatar
    robsouth
    Explorer II
    Jan 18, 2015
    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.
  • mobeewan's avatar
    mobeewan
    Explorer
    Jan 18, 2015
    Yes, you here very lucky. The water heater usually has a check valve on the hot water outlet. This will create a vacuum on the tank not allowing much water to flow out the cold water inlet to the water heater and out the low point drain. Removing the anode rod/plug on the water heater will allow it to empty to the level of the drain hole. As mentioned you should remove the anode rod at least once a year any way to inspect it. Don't leave it out over winter as others do, putting it back in will keep protecting the tank.
  • azrving's avatar
    azrving
    Explorer
    Jan 18, 2015
    Water heater is at least $350.00 plus installation. Drain plug is 2 minutes. At an RV dealer the water heater is more likely to be $750.00 plus instal as they wont give you ebay pricing. So....2 minutes or possibly $1,000
  • 12thgenusa's avatar
    12thgenusa
    Explorer
    Jan 18, 2015
    You're fine. If yours is one that can be drained that way, it works great. If yours has a check valve, it's on the hot outlet, not the cold inlet as someone said. Just remove the low point drains and flip open the relief valve to relieve the vacuum. You can also open a tap to do the same thing. The tank will drain down to the level of the cold inlet which is same level as the anode plug.

    If you're not sure how well this works, do it once and then pull the anode and check.

    Yes, you should still check the anode once a year or so. If you're one who likes to leave the tank empty between trips, it's an east, non-messy way to do this.
  • joebedford's avatar
    joebedford
    Nomad II
    Jan 18, 2015
    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?
  • enblethen's avatar
    enblethen
    Nomad
    Jan 18, 2015
    You were lucky!
    Pull the drain plug or anode depending on make. Replace anode if necessary. Replace the nylon plug if corners are getting rounded, don't use a metal plug.

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