If I am going on vacation for an extended period during winter (it occasionally gets below freezing here), should I turn off water valve AND the gas water heater or just turn off the main water valve? I am seeing a lot of people advising to close the main water valve but leaving the gas water heater on "pilot" or "low". I am worried because what if a water line bursts and drains the water out of the water heater? Wouldn't it damage the water heater? Please advise. Thank you, RK.

  • 1
    There's no harm to turning off your hot water heater if you want. You'll just have to light it again when you get home. People are probably advising you to leave it on pilot so you can just turn it back up when you get home.
    – DrewJordan
    Nov 20, 2015 at 14:11
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    If you turn it off, you should open one or more hot water faucets. It won't hurt to leave it on pilot with the main shut off, the gas supply to the main burner will not open and the small pilot flame will not cause damage even if the tank somehow emptied (which is unlikely as the main is shut off and a downstream pipe failure would only gravity drain that section of line, not the whole tank). Nov 20, 2015 at 19:28
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    @JimmyFix-it What's the reason to open hot water faucets?
    – gregmac
    Sep 23, 2016 at 16:37
  • @gregmac, I'd guess that it lets air into the system to prevent a leak from siphoning the tank dry.
    – sh1
    Dec 24, 2017 at 4:53

3 Answers 3



  • Turn the power/gas off to the water heater.

  • Turn off the water to the building.

  • Remove the water from the entire building, including the water heater, toilet tanks and water supply lines.

  • Pour RV antifreeze into every waste trap, including the toilet bowls.

The building is now winterized and your safe even if the heat goes off. If the heat goes off and you haven't removed all the water, you will probably pay for it.

  • Hello again. Another good answer: thanks. Nov 7, 2019 at 11:43

some water heaters will burn the elements out if the water is off of corse this electric, If you turn the water off the safest thing to do is turn the gas valve to pilot then the burner cannot come on , and you dont have to worry about gas leask that althow are extreemly rare can happen. with the pilot burning that is not a concern,, this is what most land loards do when properties are unoccupied.saving $ also


You should winterize the system. Drain and purge the pipes and water heater as well as add rv antifreeze " pink" to the lines. I pour a few cups in all drains. A warm water heater will not keep water in pipes warm without circulation and will cause pipes to burst if cold enough to freeze and expand the water sitting in the pipes.

  • Shouldn't you use a food grade PG or glycerol here? Aug 4, 2017 at 11:42
  • very good point on the food grade glycol, However the antifreeze is only in drain lines and if properly flushing system at the beginning of the season there should never be an issue with it being ingested. Nothing is 100% but the antifreeze should never return through faucets. I say should because I've seen some odd plumbing so anythings possible but unlikely. The pink antifreeze I mentioned is for winterizing anything that has water lines that will not be used during winter.extended periods of below freezing weather draining and purging the water system with compressed air is recommended.
    – Derek
    Aug 4, 2017 at 19:20

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