My brother just replaced my 20 year old gas water heater with a new Rheem 50 gallon gas tank. Everything is hooked up the exact same. The pilot light indicator light is blinking blue and the temp is at A. When we turn on the water in the house, it is hot for about 30 seconds then turns cold (that is with only the hot side turned on). We release water from the tank and it’s hot. The flame seems more orange than blue when on. How can we tell if we have a faulty new water heater? Or does anyone know how to trouble shoot this?

  • 1
    Edit your question and include a picture of the top of the water heater showing all the connections. Commented Mar 27 at 1:42
  • 3
    How long did the tank heat up before you opened the hot faucet? Commented Mar 27 at 2:13
  • re: flame color - Is the orifice the correct type, natural gas vs. propane? Also see waterheatertimer.org/… Commented Mar 27 at 4:03
  • The orange flame is a concern, it should be mostly blue with maybe a tiny yellow tip. Have a working CO detector. Check the pipes at the tank. One should have hot or H near the base where the pipes enter. The cold water pipe should not be on it.
    – crip659
    Commented Mar 27 at 14:08

2 Answers 2


I suspect the heater is missing its dip tube so you are getting cold water at the top of the tank going straight to the outlet.


That said, your brother replacing it vs. a plumber is a clear possibility of a cause.

  • In my experience, the symptom of a busted or missing dip tube is usually warm water, as opposed to cold... Commented Mar 27 at 11:55

With 30 seconds to go cold would mean the hot a cold tank outlets are reversed. Inspect that connection. Normally the cold water comes in at the bottom of the tank while the hot comes out at the top.

Gas tank

source: gas tank

  • 2
    In the US the water comes in at the top into a dip tube that sends the water to the bottom of the tank.
    – Tiger Guy
    Commented Mar 27 at 7:07

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