what is the heat seting for water heater

One setting after vacation mode... Hot ebough

At least 60ºC (140ºF) to avoid Legionnaires' disease caused by the Legionella bacteria. If no elderly person or children are present, you might even consider hotter temperatures.

The one with the arrow

Funny I just went to check mine for fun ,the default setting on my 60 gallons electric Giant brand tank is set at 125F .Should I set it up higher ?Reading a bit about that legionnaires disease thing and they mention should be at 140F minimum

Temporel wrote: ↑At least 60ºC (140ºF) to avoid Legionnaires' disease caused by the Legionella bacteria.

+1. 140ºF is the setting recommended by the World Health Organization according to this article. Article also says that may not be high enough because the bottom of the tank may be a lower temp.

If you have a newer home in Ontario, the building code requires a mixing valve (pic below) which mixes water coming out of the hot water tank with cold water to prevent it from being at scalding levels. I'm sure some other areas have similar requirements.
[IMG]http://www.plumbinghelp.ca/images/Mixin ... MMV_M1.jpg[/IMG]

This allows you to heat the water as hot as you want to prevent legionnaires. I did the math on the additional cost of keeping my 50gal tank at 150ºF vs 140ºF and it was less than $20/year. So I set mine at 150 which is the highest setting on my tank. Although truth be told I do this to kill a different type of bacteria that causes a sulphur smell in our water.

JWL wrote: ↑+1. 140ºF is the setting recommended by the World Health Organization according to this article. Article also says that may not be high enough because the bottom of the tank may be a lower temp.
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Actually, most, if not all temp gauges and heating elements are at the bottom of the tank... Making the bottom hotter... Since heat rises, if the bottom of the tank gets cooler then the heating elements kicks in.

Also, you're afraid of this bacteria? I can think of a lot more things to be afraid of.

In Ontario, 116 cases of legionnaires’ disease have been reported in 2011. Population in 2011 was 13.3 million. So that's 1 person in 114,000 people that got it. You have better odd dating a supermodel then catching legionnaires’ disease

I would not worry too much about the setting on WH but I will water temperature is definitely a concern . It should be atleast 130 in order to prevent any bacteria growth .

In the USA, hot water tanks come pre-set to 125f, in Canada, the pre-set is 140f.

How could you presume that ?? What is your source of information . Most tanks out of box wont give you even 100 F unless set .

smacd wrote: ↑In the USA, hot water tanks come pre-set to 125f, in Canada, the pre-set is 140f.

In testing done in Quebec it was determined that the greatest risk of Legionaries disease was with electric hot water tanks. In gas tanks the risk is very low because of the way the water is heated which I guess kills the bacteria in the process. So the recommendation would be that electric tanks should be at 140 F and gas tanks can be set lower.

newlyborn wrote: ↑How could you presume that ?? What is your source of information . Most tanks out of box wont give you even 100 F unless set .

From the manual for my Marathon HWT: https://www.rheem.com/documents/maratho ... are-manual Page 3. My mistake, though, in the US, they're set at 120f. Perhaps other mfgs don't pre-set theirs?

Yeah it seems that we were on different page . I should have mentioned that I am refering GAS WH . My bad

smacd wrote: ↑From the manual for my Marathon HWT: https://www.rheem.com/documents/maratho ... are-manual Page 3. My mistake, though, in the US, they're set at 120f. Perhaps other mfgs don't pre-set theirs?

newlyborn wrote: ↑Yeah it seems that we were on different page . I should have mentioned that I am refering GAS WH . My bad

NP. We don't have gas in our area, so I often don't think of it either.

Ebeniz wrote: ↑Actually, most, if not all temp gauges and heating elements are at the bottom of the tank... Making the bottom hotter... Since heat rises, if the bottom of the tank gets cooler then the heating elements kicks in.

Also, you're afraid of this bacteria? I can think of a lot more things to be afraid of.

In Ontario, 116 cases of legionnaires’ disease have been reported in 2011. Population in 2011 was 13.3 million. So that's 1 person in 114,000 people that got it. You have better odd dating a supermodel then catching legionnaires’ disease

I am not familiar with the construction of all hot water tanks, but the article I referenced says: "However, studies in Quebec have shown, even when the thermostat is set at 60°C, a high percentage (approximately 40%) of electric water heaters remain contaminated because of the lower temperature, about 30°C to 40°C at the bottom of the tank." I don't know how/why that happens but apparently it does regardless of how hot water tanks are constructed.

I'm not "afraid of this bacteria". Where did you get that?
I do think it is wise to have my HWT temp high enough to kill the bacteria that causes Legionnaires disease. If you want to prove that you're not "afraid" of Legionnaires disease and keep your HWT temp lower, go for it but there isn't much $ to be gained.
I also keep my HWT temp high enough to kill the bacteria that causes rotten egg smell in our hot water. This bacteria is otherwise harmless, but we prefer our water to not stink like rotten eggs and are willing to pay $20/year for that.

woof wrote: ↑In testing done in Quebec it was determined that the greatest risk of Legionaries disease was with electric hot water tanks. In gas tanks the risk is very low because of the way the water is heated which I guess kills the bacteria in the process. So the recommendation would be that electric tanks should be at 140 F and gas tanks can be set lower.

I think the article indicated that all tanks should be set at 140 F, but even at that level 40% of the electric tanks still had Legionnaires bacteria.

[IMG]http://i.imgur.com/jGeXxFG.png[/IMG]
This is the only setting i can see. i have this gas heater from toronto hydro.

any ideas how much i can set them as ?

junkone wrote: ↑This is the only setting i can see. i have this gas heater from toronto hydro.

any ideas how much i can set them as ?

Find the manufacturer's website and see if they can tell you.