For some reason, the natural gas has expanded the range at which it turns on
and off to heat water.
In effect what we have now at the old setting,
1) tepid warm but not hot water when the tank has had time to cool off
2) scalding hot water if the tank has just run through a heating cycle.

How does one narrow the range setting on a Nat Gas hot water tank, so that
the low end is warmer, but the hot end does not burn you ?

On May 2, 3:00*pm, "Attila Iskander" wrote:
For some reason, the natural gas has expanded the range at which it turns on
and off to heat water.
In effect what we have now at the old setting,
1) * *tepid warm but not hot water when the tank has had time to cool off
2) * *scalding hot water if the tank has just run through a heating cycle.

How does one narrow the range setting on a Nat Gas hot water tank, so that
the low end is warmer, but the hot end does not burn you ?


You don't say what type of water heater you have, but
if it's the more common, older conventional design, you're
screwed because it's contained in the gas valve mechanism
which is replaced as a unit. And they ain't cheap.

On Thursday, May 2, 2013 3:00:47 PM UTC-4, Attila Iskander wrote:
For some reason, the natural gas has expanded the range at which it turns on and off to heat water. In effect what we have now at the old setting, 1) tepid warm but not hot water when the tank has had time to cool off 2) scalding hot water if the tank has just run through a heating cycle. How does one narrow the range setting on a Nat Gas hot water tank, so that the low end is warmer, but the hot end does not burn you ?

You might drain it to see if there is a build up of sediment in the bottom. The thermostat control can also be removed to see if it has scale build up. Most with pilot lights are mechanical. You might also be feeling the results of a deteriorated dip tube. That's the tube under the inlet that directs all the cold water to the bottom. Otherwise if the control is shot, it's pricey, not worth replacing on an older unit.

It actually sounds to me like it's your use of hot water that's causing the problem. Frequent use of small amounts of hot water can cause temperature stratification of the hot water in the tank. That's because each time the burner trays come on, they add more energy to the tank than what was drawn off in the form of hot water. The result can be water at the top of the tank that's up to 30 deg. F warmer than the temperature setting on the tank's thermostat. So, if you set your tank to a normal 120 to 130 degree temperature, you could be getting scalding 150 to 160 degree water out of it.

Here, go to A. O. Smith's technical bulletin's page he

http://www.ho****er.com/resources/pr...cal-bulletins/

download bulletin # 32 entitled "Temperature Adjustment - Residential Gas".

In that bulletin it says:

Short repeated heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the thermostat setting by up to 30° F. If you experience this type of use, you should consider using lower temperature settings to reduce scald hazards. Listed below is time-to-burn relationship for normal adult skin.
Temperature Approximate Time to produce a 2nd & 3rd
Setting Temperature degree burn to adult skin
VERY HOT 160° F About 1/2 second
C 150° F About 1-1/2 seconds
B 140° F Less than 5 seconds
A 130° F About 30 seconds
HOT 120° F More than 5 minutes
LOW 80° F No hazard
It is recommended that the lower water temperature be used to avoid the risk
of scalding. It is also recommended in all cases that the water temperature dial be set for the lowest temperature which satisfies your hot water needs. This will also provide the most energy efficient operation of the water heater.

On May 2, 4:17*pm, jamesgang wrote:
On Thursday, May 2, 2013 3:00:47 PM UTC-4, Attila Iskander wrote:
For some reason, the natural gas has expanded the range at which it turns on and off to heat water. In effect what we have now at the old setting, 1) tepid warm but not hot water when the tank has had time to cool off 2) scalding hot water if the tank has just run through a heating cycle. How does one narrow the range setting on a Nat Gas hot water tank, so that the low end is warmer, but the hot end does not burn you ?

You might drain it to see if there is a build up of sediment in the bottom. *The thermostat control can also be removed to see if it has scale build up. *Most with pilot lights are mechanical. *You might also be feeling the results of a deteriorated dip tube. *That's the tube under the inlet that directs all the cold water to the bottom. *Otherwise if the control is shot, it's pricey, not worth replacing on an older unit.

well you could add a tempering valve and set the heater to max hot and
set the valve to the hotest water you ever want.....

if the water heater is more than 4 or 5 years old its cheaper to just
replace it........

just trying to remove the gas valve or dip tube may cause the tank to
leak......