Water heater temp setting???

Jonathon Tillman

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Mar 20, 2001
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Just moved into a 2800sqft house 4 months ago that was built back in 1995.

We have a 40 gallon gas water heater/storage tank. Being that we have sewers around our neighbor hood the water pressure in the home was set much lower than 50 PSI.

We moved from an area being used to using water pressures around 50 PSI. On this home (like you would see on any other home) there is a water pressure regulator valve on the main water line coming into the home.

Using a water pressure meter we adjusted it to 50PSI. Actually the area we are in has higher water pressures than our previous home due to in ground pumps for the city water going up as high as 80 PSI. But for the price of water and sewer the home builder and previous owners had it set below 50PSI, probably around 25 - 30PSI.

Getting back on topic, when we moved in we found the water temperature of the water heater to be much above 120F. So we figured it was too hot and it was wasting fuel to maintain that high of temperature.

Well, after taking showers we found that setting it to or around 120F was not warm enough and the hot water did not stay consistent. This is where the water pressure comes in. I am figuring that with the size of the tank that we have that water is coming out of the tank so fast that it does not have enough time to heat it and not enough in the tank to supply.

So right now the water heater is back up to where it was originally around 135 - 140F. But right now I am finding that it's easy to get scolded at the water facet.

I guess the ideal remedy would be to use less water pressure or get a bigger tank.

What are your thoughts?

I just wanted to add before anyone quoted me that 50PSI water pressure is the recommended setting for homes I found off the internet. The recommended setting for a hot water heater should be set at 120F to prevent scolding.
 

ChristopherDAC

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For years, various sources have been recommending 120F to protect against scalding. As a matter of fact, however, there has been increasing concern in the past few years that this temperature is too low to inhibit microbe growth in the tank, and that it's really safer to raise the temperature into the 135-140 degree range.
 

DougR

Second Unit
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Jun 15, 1999
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354
How old is the Tank ? It maybe time to Replace it?
It's a 40 Gallon tank but might have only a 20 Gallon supply due to Sediment in the bottom of it.
 

johnADA

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Mar 26, 2006
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Is the pressure stable???

Sounds like it may not be, similar to a problem we now have locally since they upgraded it here. If the pressure changes while in use, it stirs the tank up making it mix faster, thus feeling colder. The tank should fill with new cold water at the same rate hot water is removed. Pressure changes causes the water in the tank to roll and mix.

I use a flow control valve which is set at 40 PSI, due to the fact ours varies from 45-60 PSI, incoming into the house at times due to loads on the town system. This keeps it steady and doesnt allow the roll mixing we had. Mines set at 125 and gets drained yearly so sediment doesnt inhibit the life of the tank, nor the amount of available water.
 

Jonathon Tillman

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Mar 20, 2001
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72

The pressure fluctuates. When going to use the facet sometimes the pressure will have a lot of buildup and then go back down to the normal range. I have no idea how high it builds up but I think it would build regardless of what the regulator is set at because water is pushing and not moving through the regulator.

We have never drained the tank since we've moved in and we are inclined it never has been based on the previous owners.

Is that the best way to remove sediment at the bottom of the tank? I heard of an anode that needed to be either cleaned or replace in a hot water heater. Maybe it was oil?

I read somewhere that by the time hot water leaves your tank and reaches your tap it has already dropped 10 degrees. Any truth to that?

Only reason I mention it is that on my tank I don't have a temp setting, only low, med and high. The only way for me to get a temp reading is at the tap.
 

johnADA

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Mar 26, 2006
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Depending on the length of the run, insulation used on the pipe or none at all, will determine the drop it will incur. 10 degrees is not abnormal under those conditions.

A flow control valve will all most eliminate the hammering effect you get due to a regulator. The hammering effect is what creates the roll in the tank that mixes the water, thus making it cooler faster than normal.

To drain a tank, depends on the type, electric or gas.Electric is easier since you can remove the elements to have access it aiding the breakup of sediment without a lot of fuse. Either way a coat hanger comes in handy to get a path to the drain where water will begin to flow. It make takes several attempts to get the water flowing decent where the hose for the drain to your crock or whatever will keep a decent flow. You just shut it down, poke, poke, poke until you get flow and let it run water through until its clean. If sediment had concreted, which is likely when it isnt serviced often, thats where and electric offers its advantage having access easier.

I switched back over to and electric due to the fact of these properties. In the long haul the electric ends up being more efficient than a gas one, but not when new and the time in which I installed it, which now demand ones are the way. I also where possible run pipe insulation to minimize the drop which allows me cooler settings to be used.
 

Jonathon Tillman

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Mar 20, 2001
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72

With that in mind what temperature should I be getting at the tap so that I can set my heater accordingly. If its 130F at the tap would it be 140F at the heater?

Should I just set it at the tap at 140F and make it less complicated? I have a sink that is right above the tank on the next floor.

What causes sediment to buildup in a hot water tank?

Is there a difference in-between a pressure regulator and a flow control valve. My home already has a pressure regulator installed.
 

Philip Hamm

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Jan 23, 1999
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Is it a gas water heater? If so, is the heater element rusty and nasty? I've seen piles of rusty energy-sapping yuk come out of old water heaters.
 

ChristopherDAC

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Sediment buildup is a real problem in water heaters, which is why the makers recommend draining them at least annually. Essentially, at elevated temperatures, the carbonates and other minerals dissolved in your water supply (here in North Texas it's mostly iron minerals rather than limestone hardness) undergo chemical reactions converting them to insoluble oxides, oxalates, carbonates, and other forms. As a result, they settle to the bottom of the tank in the form of gravel. You can easily have your tank half filled with this stuff, which will displace enough water that it doesn't heat properly, will stop the water flowing out rapidly enough (which is what your description of sudden pressure drop indicates to me), and will drastically reduce your energy efficiency.

By all means, drain it immediately.
 

johnADA

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Mar 26, 2006
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Too many variables for me to say exactly what you would want it set it. You should set it, if your not planning on insulating the pipes, to aid it at a comfortable level at the furtherest usage point.

Water is full of chemicals of all types and storage points and or heating it changes how they suspend in the water and drop out. You could easily depending of what your source water carries, have a half tank full in which if its a gas heater has to heat that before it reaches and heats the water.

Simple form- And still not easy!!
Pressure regulators control pressure.
Flow controls, control the volume.
Both interact with each other, increases in flow amounts lead to higher pressure, and visa versa, lower pressure drops volume amounts.

Plumbers dont give a dam since its over there head and just protect the pressure end so faucets, pipes etc dont lead to leak problems. But without flow considerations like back pressure, which throws the whole thing outta whack, pressure along with volume spikes causing hammering. Hammering is the noises you hear from faucets and pipes as both pressure and volume settle, sounds like a hammer hitting something.

You want consistent flow volume and pressure so one doesn't contribute to the other.
 

DougR

Second Unit
Joined
Jun 15, 1999
Messages
354
Your Best and most logical choice would be to just have a New Water Heater Installed. If you think the Previous Owners didn't drain the the tank annually,then there is no doubt there is a whole lot of sediment built up. Draining it right now will not remove it all. It has already become a Solid Chunk just laying there.
Unless you like running around in circles, I would start with a New one!

http://www.homeenergy.org/archive/he...96/960510.html
 

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