How hot on water heater setting?

[Richard]

I put a new 80 gal heater in last summer. We're on a well.

BECAUSE of being on a well, I always figured that was my problem (very cold water mixing in with hot)

"Problem": To take a hot shower we use roughly speaking, 80% hot water and maybe 20% cold. Mind you this is NOT a steamy shower, just a comfortable one.

Situation: Today I'm finally installing the shower fixtures on our new shower. It's got a temp control with numbers on it. I'm supposed to set water temp to 100 degrees via a thermostat in a glass and when it's 100 degrees, I set the temop dial and the shower is 'done'.

Ok, well during this process I have been able to figure out that I can NOT get my water temp OVER 100 degrees with FULL hot.



Then I put what I think are 2 + 2 together...

My guess is the new water heater came from the factory with the temp set around 100 degrees, this way they can't ever scald someone from a factory setting.

I've not looked at my heaters settings to know what it might say its set on.

My question is... what should the temp be set on for every day living?

I know the answer is in part, "it depends..."

No kids around, just 2 adults in the house. I don't really want my shower to be 90% hot feed and 10% cold feed. On the flip side, I don't really want to keep my 80 gallons of hot water at 200 degrees (sarcastic number).

110??
120??

It's an electric heater if that helps.

 

[kennyd]

Not a for sure answer, but I know when my wife was doing in-home child care the licensing department made sure our hot water was 120° MAX. I think I have it set at about 140° now, but I like HOT showers

 

[randy41]

i think if its not set high enough you will get bacteria growth in your water heater. high enough being 130.

 

[Richard]

Wow, bigger differences than I'd expected from what I'm getting.

I'll need to take the cover off tomorrow and find out at least what mind is set on.

Thanks!

 

[ultrarunner]

Somewhat related... When I managed rental units I often would receive complaints about scalding water in units with individual water heaters and these units would have much higher than average water faucet drip problems due to the high heat.

The problem was because the residents would often turn the dial to MAX and the water would come out steaming.

My solution was to pop-off the thermostat dial, loosen the nut securing the dial assembly and recalibrate the heaters maximum temperature to 130 F and verify with a thermometer. 130 was the temp being recommended by Dish Washer manufacturers at the time.

Never had any problems with leaks or scalding water after that. In all, I reset over 40 individual water heaters.

The calibration on your heater is not accurate and it should be a simple mater to reset with a small crescent wrench and a thermometer to verify.

 

[MikeD74T]

Richard, You need to determine what your hottest need is and how much is needed at that temperature. For example a dishwasher should have 140F inlet unless it has a supplemental heater built in. You set your HW thermostat for 140 and you temper for other uses. If that meets your needs, you may be able to disconnect the lower element. No point in heating 80 gallons if 30 is enough. The HW heater & the electric meter don't care if you heat a lot of water a little or a little water a lot. If you & wife use most of your hot water in a short period during the day you may need more at a lower temp or less at a higher temp, i.e. showers, dishes, laundry all in the evening after work. Lower heater temp looses less heat thru the tanks insulation but requires more water to be heated ( but not heated as much). Some Electric COs offer off peak HW, the lower element is on a timer & is metered at a lower price. If so , set the lower thermostat higher & top element at your minimum need. You may also want to shift your greatest usage to the off peak time slot. You can also set the HW heater to the highest need & put in a tempering valve for other domestic use. That's comonly done when domestic HW comes from a 180F+ boiler system. In warm climates some install an uninsulated tempering tank before the HW heater. This allows the atmosphere to preheat to ambiant before using energy. MikeD74T

 

[Soundguy]

That's a real tossup. If you have kids or elderly.. or anyone with reduced nerve sensation.. the 'safe answer is to set the water temp lower than 'scald' level.

Keep in mind that a water heater is decently insulated.. and it will keep that water hot for a good amount of time.

I upped out water heater temp for 1 reason. My wife had an extra large garden tub installed, and filling it up and making it hot enough for her pretty much uses all the hot water.. or more! So i uppe dthe temp so we can mix in more cold so that either some hot water is leftover.. or so that it actually has enough hot water for the tub.

Was easy to set the 2 dials on the water heater.. takes only minutes to do so.

Soundguy

I put a new 80 gal heater in last summer. We're on a well.

BECAUSE of being on a well, I always figured that was my problem (very cold water mixing in with hot)

"Problem": To take a hot shower we use roughly speaking, 80% hot water and maybe 20% cold. Mind you this is NOT a steamy shower, just a comfortable one.

Situation: Today I'm finally installing the shower fixtures on our new shower. It's got a temp control with numbers on it. I'm supposed to set water temp to 100 degrees via a thermostat in a glass and when it's 100 degrees, I set the temop dial and the shower is 'done'.

Ok, well during this process I have been able to figure out that I can NOT get my water temp OVER 100 degrees with FULL hot.



Then I put what I think are 2 + 2 together...

My guess is the new water heater came from the factory with the temp set around 100 degrees, this way they can't ever scald someone from a factory setting.

I've not looked at my heaters settings to know what it might say its set on.

My question is... what should the temp be set on for every day living?

I know the answer is in part, "it depends..."

No kids around, just 2 adults in the house. I don't really want my shower to be 90% hot feed and 10% cold feed. On the flip side, I don't really want to keep my 80 gallons of hot water at 200 degrees (sarcastic number).

110??
120??

It's an electric heater if that helps.

 

[schmism]

i run mine hot 130-140

i figure i use less hot water if i mix 140 deg water with 60 deg water instead of 110 deg water with 60 deg water.

 

[Farmwithjunk]

Mine's set at 140. We have anti-scald shower controls. You can't start off with full tilt hot at the showers no matter what. They will GRADUALLY work up to around 110/120 degrees. Kitchen faucets are another story. VERY hot if you want it.

 

[rosietheriviter]

Not a for sure answer, but I know when my wife was doing in-home child care the licensing department made sure our hot water was 120ｰ MAX. I think I have it set at about 140ｰ now, but I like HOT showers

Kennyd,
If you take a cooking thermometer and immerse it in your hottest water AND try to keep your hand immersed in the same water at the same time, I believe you will find a temperature around 115 to 120 to be the maximum you can tolerate. Of course there will be variations between persons. But if I remember correctly - 125 degrees F. is the water temperature we used to "scald" hogs we had butchered.

On a different tack, the higher the temperature of the water, the faster it's BTU content will dissipate to the surrounding air/etc.

I takes one BTU to raise one pound of water one degree Farenheit. Your bathing/washing activities will use x number of BTUs and it will not matter one bit if you are heating all the water to x degrees or just some of the water to x plus 50 degrees and adding cold water.

The 140 degree water will radiate more heat from the storage container (water heater tank) and from the piping runs than will 110 degree water for instance. Since the hot water demand is so very short term in most households, I would opt to have the hot water thermostat set at about 10 degrees higher than my maximum desired usage temperature, assuming I had the storage capacity to get me through a shower and/or dishes, etc.

If your water heater is in a location that permits the heat to radiate into your living quarters, a higher storage temperature COULD be better in the winter, but definetly NOT good in the summer.

The most important thing to remember is, measure your actual water temperature, and verify that it is the temperature you are comfortable and safe with. The numbers on the thermostat are not at all accurate, they are repeatable though.

Rosie