Plumbing in the Home/hot water tank


Whirlpool 40gal gas.  
 When the tank heats up to prescribed temperature setting on the dial the pilot light goes out.  If I wait 10 minutes usually it will relight.  Push button ignitor.  
 What I have been doing lately is slowly heating the water incrementally starting just above vacation mark on the dial and slowly turning up to 120 degrees or the "warm" mark on the dial.
 It's a full day process going back and forth keeping an eye on the tank to raise water temp.  The showers, laundry and dishwasher use most of it then it's "keep an eye on it again" time to re-raise the temperature.      
 There are no leaks underneath and the under screen is not clogged with dust.  If I turn the dial to high it will heat for a while and shut off for whatever reason.  For me, it's better to start low temp. and work it back to a higher temp.  The tank is 4 1/2 years old. and it's been doing this for about 2 months off and on.  Is there a fix?

Duke, The problem you describe can be caused my several things so we can start with the most common. The pilot light is controlled by the thermocouple. It, in turn, controls the gas valve. If the thermocouple is not hot enough, the gas valve is de-energized and shuts off gas supply to the burner. It's the primary safety that keeps the tank from over heating. The secondary control is the gas valve itself. It is controlled by water temperature. When the pilot thermocouple is on it's way out(a very common occurrence)sometimes the burner heat is enough to complete a cycle and bring the water to the set temp. Start by replacing the thermo couple and be sure that the last 1-1/2" of the tube is completely engulfed in the flame. It should glow very bright red when the pilot is burning. Be very careful replacing the thermocouple so as not to strip any of the threads during reassembly. Unless you are familiar  with this process, call a qualified plumber.


Plumbing in the Home

All Answers

Answers by Expert:

Ask Experts


Jay Nicholas


Plumbing & Heating (warm air, hot water & steam heat)


40 years in the business, 35 years as a lic. master plumber in NY State. Retired

Graduated Magna cum laude at the School of Hard Knocks

Past/Present Clients
Commercial, residential and light industrial. You name it ...I have probably worked on it

©2016 All rights reserved.