Correct Temp. for hot water heater

[gray wolf]

Seems to be conflicting opinions on the correct Temperature for Electric hot water heaters.

Some in the know say 120*F is OK and reduces chance of burns from to hot a temp.

Others say 140*F to reduce chance of sickness from water born pathogen ( Legionnaires disease )

I am not able to install a mixer >( $$$ ) So I am thinking 135*

My landlord put in a new hot water heater, the old one broke.

I checked the water Temp and it's a tad less that 140* 3 feet from the tank.
It's doable for us and we are OK with being careful not to get burned.

Problem # 2

She also replaced the two single faucets in the bathroom sink, one hot and one cold ( what a pain that is )
Have to mix the water in your hand.

The faucets have replaceable easy on easy off cartridges, they work OK but the hot water faucet has started to squeak when you turn it on and off. It seems the hot water is causing the plastic to swell (get tight ) and the plastic, (could be Nylon) is rubbing against itself.

?? #3

Is there any kind of simple gadget that can connect the two faucets together so the hot can mix with the cold ?
Some kind of clamp on easy thing.

Thank you for the help men.


Sam

[C.F.Plinker]

I tend to go along with the 120* folks. Why pay the electric company to keep 40 or 50 gallons of water at 140* or more all day and night when you are going to mix it with cold water when you use it. I set mine so it is at or just above the hottest temperature I will use.

As far as pathogens are concerned I have to wonder where they are getting into the water system from. If they are in the water system they will be throughout the cold water piping anyway. While you might kill the ones in the water tank itself, could they grow in the hot water pipes as the pipes cool down once you turn the hot water off.

[2wheelDuke]

I think mine is set at 125 degrees F by default. I turn my shower on to full hot and don't get burned, but the girlfriend has to turn the cold on a bit to tolerate it.

[srtolly]

Interesting subject. In my line of work the state tells us to keep water temp at 110. We push it to 115. I work with folks that have developmental disabilities so safety is the main thing.

[Vann]

Here's food for thought, learned this in safety training.

Hot water can produce first degree burns within:
5 mins @ 120F
20 seconds @ 130F
3 seconds @140F
1.5 seconds @ 150F
and in less than 1 second @ 160F

I'm not trying to be a know it all, but it is something to think about if kids are around. Personally I keep mine at 125F simply because I don't like getting scalded when someone flushes the toilet.

[oneokie]

Another vote for 120*. If one is concerned about water borne pathogens, most county health departments will test a sample for little or no cost. What is the source of this water? Well, pond, spring, creek, river, cistern?

[Pipefitter]

If you are on a well, you can chlorinate the well easy, search youtube. As for the squeaky faucet get some silicone faucet and washer grease and lightly lube the cartridges.

[KAF]

Why would anybody need to heat hot water? I have a water heater..... 120

[gray wolf]

Water is from a dug well, all of it is filtered before ingesting.

We have been using a big Berky free standing ceramic/silver impregnated gravity filter for 12 years now.

Last check the temp. was 130*F I think I will leave it this way unless problems arise.

[William Yanda]

Pathogens are not necessarily water borne. I recall the Dr. advising us to raise the setting from 120 to 140 when my sister was diagnosed with Hepatitis. The intent was to better sanitize the dishes when washing. A dishwasher may have also been advised at that time.

[runfiverun]

depending on the faucet style and height you may be able to rig something up with cut off garden hoses a 'Y' to screw them into [from the garden hose center] and some hose clamps.

other than that you're gonna have to use a stopper like we did in the old days.

[dragon813gt]

Why would anybody need to heat hot water? I have a water heater..... 120

Beat me to it. Calling them hot water heaters is one of my pet peeves.

There are other reasons to keep the temp hotter and then mix it down. One of the main ones is recovery rate. You increase your recovery rate by keeping the tank hotter and mixing it down.

Every time you turn on the hot water faucet you use hot water from the tank. This in turn is replenished by cold water. If you don't mix it down it's a one to one ratio. So if you have a 40 gallon tank, get a shower that uses 20 gallons, you now took half the hot water out of the tank. The cold water mixes w/ the hot water that was remaining in the tank. None of this is static and the tank is constantly being replenished w/ cold water.

Now mixing it down can be different ratios depending on how you set it up. But as an example you used 20 gallons to take a shower. Since you were mixing it down you only pulled ten from the tank. So the tank was replenished w/ ten gallons of cold water instead of twenty.

Apply this to larger tanks like 60 and 80 gallons and you can see how your recovery rate will be a lot higher. The fuel source will be used less because you don't have to heat the water up as much. I explained all of this in a thread like this a few months back.

Mixing it down is going to become more common because of the new efficiency regulations. A standards 80 gallon electric water heater w/ two elements has gone the way of the dodo. When existing stock is used up that's it. Any 80 gallon electric will be a heat pump. These create a whole different set of issues. So you will start to see 60 gallon heaters w/ mixing valves so you end up w/ the same recovery rate.

Mine is mixed down. I never run out of hot water. Even w/ a 14yo girl that lives in the shower. Like I said there are other advantages to mixing it down. A Honeywell Sparco mixing valve is extremely easy to rebuild. If you buy one w/unions you can replace one in about a minute if you have ball valves in the system. I had to replace the o-rings in it after about eight years of use. That's all the maintenance the mixing valve has required.

[pworley1]

I keep my water heater set at 120. If I understand the faucet question correctly,(a hot water faucet and a cold water faucet independent of each other) I would replace both with a regular set of faucets.

[RED333]

You pic the temp, I use 120 to 125.
On the mixing hot and cold water, gona be tuff above the sink.
However it can be done below the sink, Lowes or Home Depot
sells 3/8 compression "Tee" you will need one.
Also get 2 3/8 compression lines, they have the fitting built on to the line.
Connect the hot and cold from the wall, put both lines to the "Tee".
Connect the 3rd fitting off the "Tee" to the of the valves on the sink.

[CastingFool]

a lot of newer shower faucets have an anti scold feature on them, so you can set the t-stat on your water heater at 140 deg. and adjust your faucet to deliver 125 deg water.

[GhostHawk]

Well I like my water hot, so mine is set a touch over 130, which is considerable over the guidelines.

But it is a fairly long run to both kitchen and bath. Closest tap is the clothes washer and even that is a good 12' from the heater.

In 17 years no burns, no accidents, no problems, but it is too hot for comfort straight up hot once it warms up.

On the plus side hot showers can be HOT.

[gray wolf]

depending on the faucet style and height you may be able to rig something up with cut off garden hoses a 'Y' to screw them into [from the garden hose center] and some hose clamps.

other than that you're gonna have to use a stopper like we did in the old days.

Yup, I had the same thought, and the Landlady is not going for anything >$$$
So any kind of plumbing is out, the sink is an old sink and it can't be set up with a single faucet.

Don't even have a Vanity, I think that's what you call it when a sink has a cabinet under it.

Poor at 73 does have some disadvantages, but hey ! Julie and I made it thus far so I guess we can go on a little longer.

Don't read the above as crying in my Beer. We are very grateful folks and thank god for whatever we have.

I appreciate all the advise, you folks are always helpful.

Sam

[TXGunNut]

I set mine @ 120 when I replaced my leaky 50 with a 30. It has two elements and I use low-flow shower heads. I live alone but when I have a houseguest 20 minutes is plenty of time between showers for recovery.

[MaryB]

Mine is a tad over 140... I like hot showers and hate running out of water. With a bad back I use a shower massage head to loosen things up so can be in there awhile... what is the spacing for the faucets? Otherwise you could remove the aerator and screw on a dishwasher fitting, then find some used dishwasher hoses from a local appliance store to make up a y adapter...

[Mtnfolk75]

Our's is a 50 gallon Electric set at 140*, SWMBO and I are the only residents. We came shower back to back and not run out of hot water, in fact a few weeks ago we had a couple of old friends spend 3 days/2 nights with us. On the morning of the 3rd day, 3 showers were run almost back to back with no loss of temperature. The water heater is under the cabin, the run to the kitchen is about 16', the bathroom sink about 18' & shower is about 14'. Also with the cabin being 538 Sq Ft, we do not have a tub due to space ...... [smilie=s:

[jsizemore]

If the existing faucets have aerators then you can convert them to accept a washing machine 'Y'. Usually doesn't get wife approval. You could get a single lever faucet that uses a single hole mount and get a blanking plug for the other hole like you see for kitchen sink spray attachment holes.

If your hot water doesn't get used on a regular basis then you can set it for 140F+ to kill bacteria that can give the water that rotten egg smell. If used regularly, then most larger municipalities call for at least 120 and no more then 130. Most new W/H I install are preset at 125 right out of the box.

[Pipefitter]

Electric water heaters with 2 elements only use one element at a time. Cold water is introduced at the bottom of the tank, hot water is drawn off from the top. As you use hot water the cold water at the bottom of the tank gets heated by the bottom element, if you draw enough hot water from the tank the top thermostat switches the power to the top element. This is why the bottom element is usually the one that needs replacing when you have no hot water.


The best way to keep a water heater for 15-20 years is to drain 10-15 gallons from the drain valve once a month. This keeps the lime and other sediments from clogging the water heater. (The water heater in my house is over 30 years old and we have 19ppm calcium and 6ppm iron from the well water)

[gray wolf]

Thank you all for the great information.


Sam

[osteodoc08]

120*F is the textbook answer.

[Dale in Louisiana]

Why would anybody need to heat hot water? I have a water heater..... 120

Although it's a departure from the original context, just because I KNOW these things, in steam powerhouses we use waste heat to preheat the feedwater so that when we send it to the boiler to make steam, it already has a lot of heat in it. We (that's YOU) pay for the energy to heat it the rest of the way into steam, so capturing those otherwise wasted BTU's saves us all money.

But in this conversation, I'm with you.

dale in Louisiana
(who ran around too many powerplants)

[dragon813gt]

You're also preheating the water in steam boilers to prevent shock. You can't just add cold water to a boiler that's up and steaming. Well you can, but it's going to make a lot of noise. When performing annuals they always sound like they're going to break themselves apart when getting back up to temp. Water hammer is an understatement :)

[iomskp]

You are so lucky here in Australia it is Law that all new water heater installations and replacement, are either factory pre set to 50C (122 F ) and are non adjustable, or you have a tempering valve fitted again pre set to 122 F at the sink, the down side of that is most units deliver the water at 122 F at the heater outlet so when the water arrives at the sink it is too cold to wash your clothes or to do the dishes.