Gas Water heater runs out of hot water too soon

I have a Bradford White 50 gal gas water heater that appears to run out of hot water after starting the second shower (15 minutes of use). Wondering if it might be the thermostat or dip tube? Pilot stays lit, but you have to crank the thermostat well past safe range of 120 degrees F to keep the burner on yet it still does not heat water up adequately.

Any thoughts or suggestions for troubleshooting are appreciated.

How old is it? It may be filled with debris…

Yes Sounds like the dip tube taking the cold water to the bottom of the tank has fallen off … Roy

I agree with Mark. Sediment buildup in the bottom of the tank. Try flushing the tank out, if possible, and see if it improves. If water runs freely when flushing and no improvement, prolly a gas control issue. Doubtful it is the dip tube. You would have issues five minutes into the first shower, not just after fifteen minutes in the second shower. Besides, cold water will naturally sink and hot water naturally rise. Flowing water will keep it churning and mixing.

Don’t spend any money on it if it is already past its expected lifepsan of 10-12 years. This is especially important if its located in the attic or on the same level as the living area. A safety pan (if present) has its limits too and will not catch all types of leaks.

If you give us the serial number we can figure out the date of manufacture.

I vote dip-tube.

If you’re getting 15 minutes of hot water, it probably broke in half, rather than at the top of the tank. Replace the water heater.

What is the rated flow of the shower head? You may just flat be using all the hot water and the recovery rate is slow.

Are there boiling, gurgling sounds when it is heating up? That is an indication of sediment build up.

Like stated earlier post the Serial number (it starts with a letter) and that will give the age.