How hot is the hot water in your home?

[LVSteve]

Had our gas water heater replaced after it let go at the beginning of January. I had a 50 gallon, 40,000 BTU Rheem unit fitted. The guy set the thermostat to "A", which according to the manual, should have the water at approximately 130°F. All I can say is that using that setting the water freakin' hot compared with the old unit.

I dug out my pyrometer and found that the hot water in the closest bathroom to the heater was running at 134°F. Hmm. With measurement errors I'm not sure that what the pyrometer is saying is that far out of line with the thermostat. But, I still felt that the water was too hot, so I turned the stat down a bit. This lowered the temperature in the near bathroom to 129°F.

Just for completeness, I measured the temperature in the more far flung parts of the house. The longest run to the kitchen showed 120°F, with the upstairs bathroom at the back of the house reading 123°F.

What do you run your water at?

 

[444 Magnum]

120 degrees was the standard unless it's changed. The shower's have scald guard protection so you don't get burned by them. Faucets and tubs are the only danger for children. 120 degrees shouldn't be a danger for anyone but hot enough to be comfortable.

My son has always had his dangerously hot. I tried to get him to turn it down for years but he refused. My grandson is now 6 and they've finally turned it down. I wonder if there was a scalding I was never told about?

 

[oldbrownhat]

I think my HW tank is set for 140º. Haven't actually measured the output at any of the faucets, but it's a small house and the runs are fairly short.

 

[Old 44 Guy]

My hew tankless is set at 120 and that is just right.

 

[Rudi]

Mine is electric. I have to keep it at 120 or the breaker pops. I'd rather have it at 140.

 

[chief38]

In my last home (very large home) we had a 100 gallon "Super Store Tank" which is basically a non powered, super insulated giant thermos bottle to store hot water. The water was heated up by the gas fired boiler and then stored in the Super Store tank. Because of the very real threat of Legionaries Disease living in a tank, I set the super store temperature to 145ºF at which all traces of Legionaries dies. Since we had no young kids at home, the high temperature was no danger and in all the showers were thermostatically controlled shower body valves that kept the water temperature from fluctuating when someone else in the house turned on or off the hot water.

In our current home, we no longer have a hot water tank and there is no stored hot water. Instead we have a Rannai wall mounted instant and endless gas fired water heater. Since the unit stores no hot water at all, there is no reason to worry about tainted water. That unit is set to 120ºF and supplies us with endless hot water on demand.

BTW, anyone who is in the market for a new hot water unit, might want to look into the Rannai tankless hot water heater system. Not only does it work great, the unit is only about 15" wide x 25" high and stands off the wall around 10". They say if properly maintained (flushed out yearly - takes 1/2 hour to do) the unit should last well over 20+ years. I also love the fact that there is no hot water tank taking up space, developing leaks and getting in my way in our garage.

 

[Ivan the Butcher]

20 year old gas 40 gallon tank set at "A" Which is just right according to Goldie Locks. That was 133* F at the kitchen faucet. I think I'll turn it down a little bit, but from previous experience very much and the stat sticks off. Momma Bear gets grumpy if she has to take a cool let alone cold shower!

Ivan

 

[Nevada Ed]

When my bathroom mirrors fog up and the hallway smoke detecter goes off;

I turn down the water temperature, until Spring comes back.

 

[STCM(SW)]

Tank less water heater are ok unless you live ware it gets really cold.
My 75 gallon water gas heater does not come on that often and does fine if I clean it once a year.
4 gallons of vinegar helps with the hard water we have here...

 

[Onomea]

I have mine set at, when it gets up to the second floor, "darn hot" as measured by the finger under the tap test. Don't use "as is" except for shaving.

 

[LVSteve]

120 degrees was the standard unless it's changed. The shower's have scald guard protection so you don't get burned by them. Faucets and tubs are the only danger for children. 120 degrees shouldn't be a danger for anyone but hot enough to be comfortable.

My son has always had his dangerously hot. I tried to get him to turn it down for years but he refused. My grandson is now 6 and they've finally turned it down. I wonder if there was a scalding I was never told about?

Yes, it's visitors and children that concern me, too. I get that having hotter water means that less hot has to be mixed with the cold to get a good shower, and the tank is less likely to be drained by successive users. As 99% of the time it's just my wife and I here, I'll keep the stat turned down and save a bit on my natural gas bill. The water is still hotter than the old setup.

As set up by the installer, the water in my downstairs bathroom it seemed crazy hot to me. The instruction booklet showed how long it takes to cause a major burn at the different temperatures. The time drastically increases as you get down to 120°F or less. Conversely, for a temperature increase from 130°F to 135°F, the burn time got scary short.

 

[SweetMK]

For me,, there are two temperatures to think about.

1) Threshold of pain that ends up being 107 degrees F

2) Minimum domestic hot water temperature is 120 degrees F due to bacteria growth.

So, based on those two temps, we keep our water heater set at 122 degrees F

At 122,, it takes more than 3 or four seconds to be REAL uncomfortable in the shower.
That is long enough to adjust the temp, or get out of the way.

The other reason to keep the temp low is that it saves LOTS of $$$$,,

 

[coltle6920]

For me,, there are two temperatures to think about.

1) Threshold of pain that ends up being 107 degrees F

2) Minimum domestic hot water temperature is 120 degrees F due to bacteria growth.

So, based on those two temps, we keep our water heater set at 122 degrees F

At 122,, it takes more than 3 or four seconds to be REAL uncomfortable in the shower.
That is long enough to adjust the temp, or get out of the way.

The other reason to keep the temp low is that it saves LOTS of $$$$,,

My thoughts exactly. You're going to have to mix in cold water anyway to bathe or shower so why heat it higher than necessary when not in use.

Maybe someone in the know will explain the need for the wide variance in temp settings on a water heater.

 

[Harrison]

We have had a gas tankless hot water heater for about 10 years. It is a big money saver. Set at 130 degrees. That way our shower mixes enough cold water with the hot to have a comfortable shower without running the heater full blast and wasting gas.

 

[bullmack]

As previously stated 120° is the minimum temperature to prevent legionella. I keep mine at 130° to be safe. Legionella is nothing to mess with!

 

[mtgianni]

140 used to be the standard but a lawsuit in which a immigrant left her child in the tub and answered the door left the child with burns and webbed feet. Now 130 is the standard. Mine runs about 125 in a 50 gallon tank.

 

[Yaworski]

120 makes a good breeding ground for bacteria. I turned my water heater up to about 150. My skivvies are whiter now.

I do my dishes by hand with only hot water. They come clean and dry quickly.

 

[Yaworski]

140 used to be the standard but a lawsuit in which a immigrant left her child in the tub and answered the door left the child with burns and webbed feet.

Webbed feet?

 

[Rotorhead1026]

My hew tankless is set at 120 and that is just right.

125F on mine, but there are no children in the house. It’s really easy to change, too.

 

[ameridaddy]

My electric does 145 deg F in summer, heating system boiler with a water coil does 185 deg F in winter. No kids, no problem.