Have the typical vertical cylinder gas fired house hot water heater.
The thermostat on the gas control has a little raised bar on the dial
half-way between the HOT and WARM marks.
This is where it is set presently.
I am assuming that this is the typical or avg. temp. setting.
Is it safe to go, e.g., half way between this mark and
the HOT (max.) Mark ?
Half way would be approx what temp., do you think ?
Would like to try raising the temp. as the wife is always complaining
about not enough hot water.
Not sure how much to raise it to be safe; both from a scalding
viewpoint, but also for the safety of the tank.
**I wouldn't worry about the tank. The control is not going to allow you to
do something that would cause it to self destruct. Since it doesn't have
actual temperature settings, just raise it up incrementally until it's hot
enough for your needs
In the morning, I don't have to add any cold water for my shower.
But if SWMBO takes her shower first, it causes the thermostat to
kick it on, and I have to add cold water. So we see that I take mine
first, then hers about a half hour afterwards.
So before she takes a long tub bath in the evening, she makes sure
I have washed dishes or run a batch of laundry.
Seriously, it's better, IMO, to nudge the control over to the hot
then back after it kicks on, than having it be at a perpetually higher
Sounds like that is a potnetial health safey issue. The bacteria
that causes Legionares disease grows in warm water and it's
recommended that the tank be kept above 130F. That's where
mine is set. Also, it's obviously safe to set the tank thermostat
to any temp that it's capable of being set to, including very hot.
Safe that is from the standpoint of the tank, not from possible
scalding to users.
First, how big is the heater? How many gallons does it hold?
How many people in the house using hot water?
When I had 3 women in the house taking showers one after the other in
the morning (don't get exited, 2 of them were my daughters), they used a
lot of hot water.
I learned to revert to my Navy training. Wet down. Shut off water. Soap
Since they moved out (the daughters, I mean), I never run out of hot
water. I have a 40 gallon propane fired heater with 3400 BTUH input and
set at halfway between Hot and Warm..
the tank has a safety built in. I doubt you could turn it high enough
to pop the T&P valve. You might want to invest in a thermometer. And
set it where you want. 140 is a good place to start. If you have heavy
shower traffic, you might want to press it to 150.
remove the "not" from my address to email
(Resubmitted from a similar question back in FEB 11)
You have to balance two competing objectives - hot enough in the tank to
prevent the bacteria causing Legionaries' Disease from growing but cool
enough at the tap to keep from scalding (antiscald valves not considered).
To do this, check the water temperature at the hot water tap furthest from
the tank. By furthest, I mean where the hot water must take the longest
path to get to the tap. This tap is likely to have the coolest hot water as
the water had the most chance to loose heat during its travel. Use a
drinking glass with a thermometer in it and let the water overflow the glass
until it is fully hot. You want 120 deg F which is the maximum temperature
various agencies have recommended to prevent scalding. Adjust the hot water
heater as necessary
Now, check the temperature setting of the hot water in the tank. If it
is above 130 deg F, you will have to live with it unless you want to install
point of use heating. If it is below 130 deg F, you will have to increase
it to that temperature as various agencies agree that 130 deg F is the
minimum temperature needed to prevent the bacteria causing Legionaries'
Disease from growing.
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