(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 15 of 24

Thread: Water Heater Temp

Hybrid View

  1. #1

    Default Water Heater Temp

    I have a 50 gal electric water heater and my temp on my water heater is set to 130 deg and it seems that there is enough hot water for no more than 3 showers. Once the 4th person takes a shower, you have no hot water left. Should I increase the temp or it wont matter?

  2. #2
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,447

    Default

    If you have a teenager, you might run out after one shower!

    A new showerhead can't legally be sold that uses more than 2.5gpm. So, how long are those three showers and how old is the showerhead? You might want to run it into a bucket while timing it to see what you have. You can't get 50-gallons of 130-degree water out of the tank, as the incoming cold dilutes it. Figure anything over 70% a bonus.

    Yes, you can effectively make the tank look bigger if you raise the temp, but for safety reasons, you should also install a tempering valve to limit the output. They're required where I live. Basically, it's an adjustable valve that mixes some cold with the hot let and 'tempers' it so it isn't quite as hot...it's like mixing the cold at the shower, but done at the outlet of the tank to help prevent excessively hot water from harming someone.

    Last edited by Terry; 08-06-2011 at 01:25 PM.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  3. #3

    Default

    Both bathrooms have new showerheads that my wife bought at Bed Bath and Beyond within the past year.

    What's the logic in making the tank look bigger if you raise the temp?

    Is setting it to 140 degrees OK?

  4. #4
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    Quote Originally Posted by Mikeyboy View Post
    What's the logic in making the tank look bigger if you raise the temp?

    Is setting it to 140 degrees OK?
    It's all about BTU's The higher the temp of the water stored in the tank the more heat you have stored.

    You then will mix more cold and less hot so you will in effect be "Making the water heater look bigger."

    The problem is that this hot water presents a very real danger of scalding someone. Especially young and elderly people! 3rd degree scald injuries occur in about 1 second at 160F, 5 seconds at 140F, 9 minutes at 120F, 6.7 hours at 110F. Scald Information click here

    The water must be tempered to a safe temperature as it leaves the water heater when elevated temperatures are used. One of the valves pictured below would be required. Watts 70A & L70A Tempering Valve click here

    Last edited by Redwood; 01-22-2009 at 09:15 PM.

  5. #5
    Plumber jimbo's Avatar
    Join Date
    Aug 2004
    Location
    San Diego
    Posts
    9,001

    Default

    There is the 70% principal in action here. A water heater will deliver 70% of its gallon capacity, at "shower" temperature, that is within about 20 f set point. SO, you 50 gallon tank will give you 35 gallons. ~2 gallons per minute, 10 minute shower....20 gallons. You are lucky to get 3 showers, and you can just forget 4!

    There are remedies, and they have been described in the posts above mine.

  6. #6
    Extreme DIY Homeowner Scuba_Dave's Avatar
    Join Date
    Jan 2009
    Location
    South of Boston, MA
    Posts
    885

    Default

    My 50g electric indicates that it can provide 58 gallons of hot water in the 1st hour. At 20g a shower then the 3rd shower would start to go cold. I think this also depends upon how hot you like the shower
    DIY Handyman (not 4 hire)
    I have enough to do to my own house

  7. #7
    Illinois Licensed Plumber SewerRatz's Avatar
    Join Date
    Nov 2008
    Location
    Chicago, IL
    Posts
    1,705

    Default

    Quote Originally Posted by Mikeyboy View Post
    I have a 50 gal electric water heater and my temp on my water heater is set to 130 deg and it seems that there is enough hot water for no more than 3 showers. Once the 4th person takes a shower, you have no hot water left. Should I increase the temp or it wont matter?
    Turning up the temp of a water heater, you run the risk of scalding. Gamma and the water heater manufactures recommend you do not have the temp any higher than 120 degrees. A low flow shower head can help a lot and shorter showers is a huge help too.

  8. #8

    Default

    So, what's the best way to allow more people to take showers with hot water?

  9. #9
    Illinois Licensed Plumber SewerRatz's Avatar
    Join Date
    Nov 2008
    Location
    Chicago, IL
    Posts
    1,705

    Default

    Quote Originally Posted by Mikeyboy View Post
    So, what's the best way to allow more people to take showers with hot water?
    A larger heater, a lower flow shower head, shorter showers, or even add a second water heater. Two 50 in series would give you a lot of good hot water.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •