Electric Tankless Water Heater only achieves 106F. ?

This is a Stiebel Eltron 24 that uses 2 - 60 amp double pole breakers and #6 copper wire located only about 5' from 200 AMP modern Square D service panel. Total of 4 conductors and 1 ground. All 4 conductors have 121.5 v between conductor and ground and 243 V between conductors. There is no voltage drop from panel to heater....and no voltage drop at breaker or heater when unit is turned on. Input water temp is 55F. Each conductor draws 13 amps when heater is set to max 125F........and output temp achieves only 106F at 1.5 GPM. When warmer 90F water is input to unit....it still only achieves 106F.....and draws less amperage. It appears this unit is only trying to achieve 106F. I have exchanged the unit with manufacturer and the new unit does the same thing. Manufacturer says the unit I returned test OK in their lab....at 208V it makes 125F water at 3.5 GPM with 46F water input.

I'm baffled......what conditions could exist at my house to limit this unit to 106F out put? Why does the unit only draw 13 amps if it really is trying to make 125F output water.....it should be drawing close to 50 amps on each conductor? Why are both LEDs on the unit on solid.....indicating they think they can achieve the desired stting output temp. Im located in Montana at 4600 feet......would that screw up anything? All connections are tight, I replaced the breakers just in case. The output temp is measured directly at tank so there is no loss in the pipes or mixing issues. I'm baffled and the manufacturer help line.....while very helpfull is also baffled. I called an electrical engineer / master electritian who was very nice and had me verify the voltages over the phone.......he said they are fine and he sees no external reason unit should not perform. He asked me to check with Stiegel to ensure unit would work ok at 243 V.......they said 243 is fine and they have units working at 250V.
Thanks for the input guys....let me answer your questions......

No its not a flow issue.....it produces 106 F water at 1.5 GPM or 3.5 GPM.

No the input and output are not reversed....same as diagram and verified by tech support.......right is input, left is output.

As I stated...I sent back a unit that did not work at my house....and did work at the manifacturers lab.....so it would not seem to be a defect in the unit.

Does anyone have any ideas what external factors may cause this condition and ways to diagnose them?
The solution to the problem was plumbing. I reported earlier that the water temp was measured at the out put of the unit.....therefore eliminating heat loss in the plumbing and any issues with mixing valves that existed in the plumbing. However......I did not isolate the plumbing by turning off the valve below the test port.....so I was getting mixing backflow. It turns out a mixing valve at the output of my propane hot water tank was mixing the 145 F water output of this tank to an acceptable tempurature.....but was mixing the 125 F water output of the tankless heater to 106 F. Thanks for all the input.

Here is my story.....
Ok so we bought our house about 3 months ago we right away noticed dishes arn't getting as clean and the water tastes a little different and we figured we had bad water. One Saturday morning I woke up to a nice cold shower becaues the calcium build-up on the elements shorted them out. I drained the hot water heater replaced the elements and the sediment in the bottom of the hot water heater was terrible I cleaned it out the best I could. So I now I know I have really hard water as we had the sellers replace the hot water elements a week before we moved in and it only took 3 months.
To my questions.....
I have no experience or a clue on what grain system to buy. It is just 2 adults averaging no more than 3000 gallons per month or less. I would like to get a system to withstand 2 adults and 2 children at least so lets say 6000 - 7000 gallons per month. How do I gauge on what size system I need?
I'm am mechanically inclined and my father is a plumber so I am not worried about the installation part.
Is it safe to drink/cook from the softener if I pipe the entire house through the softener?
At this point with all the terrible build up in the hot water heater I plan on getting a new hot water heater at the same time as a softener and redu all the piping at once because my 50 gallon hot water heater is probably 40 gallons from the sediment build-up I'm sure.
They advertise that the water softener can save money because the water is not as "thick" and will not use as much energy to heat in the hot water heater is this true? Has anyone noticed a difference? If for some reason its not good or you are not suppose to drink water from the softener what if I drank the water directly from my fridge which also has a filter would this then be fine?

Sorry I am new to the water softener stuff. We are also thinking if we have to spring the money for a new hot water heater to go with a on-demand hot water heater or "tank-less" anyone see any real savings with tankless heaters?

Thank you for your time.

Propane water heater Starts out Cold?

Propane water heater Starts out Cold and after the first person takes the cold shower and maybe 10 min later the second person showering gets a hot shower. It is rare for this to happen but it does. I’m going to flush the tank tonight. I’m thinking it is an intermittent problem with the thermostat???

on demand water heater?

do you know of any that do not need to be vented?
i did a stupid thing and bought a tub thats damn near the size of a pool, and my tank cant keep up i use at least two full tanks, ouch when the power bill comes in:( and this house is old and has enough holes in it. i would rather not add another by venting:)
thank you.

HI, I am wondering if the fuel and the cost are the same or similar (is the propane used for a home lpg hot water heater the same as used in the small white tanks we refill?) thanks jerry
thanks everyone. To propane man...the tank I refererred to came with the grill, it is an outdoor grill with little lava type rocks?you have heard of these? I did not have to change the connection at all it came set up.

I live in a 32 unit apartment building that has hot water heated by two tank-less hot water heaters. My apartment rarely gets hot water but none of the other tenants have the same issue. The hot water is paid by the owners. When I turn the hot water on all I get is lukewarm to cold water, very rarely does it come out hot. At night, during the a.m. hours, there is no hot water at all. There is a maintenance worker who lives on site and I am convinced that he, at the demand of his employer, does something to it somehow.

I'm thinking of buying a tank-less hot water heater for my whole house but i've read that the natural gas heaters don't put out the flow that they advertise and it is best to go with an electric.I have a 40 gallon electric now that i bought 2 years ago.It is turned up all the way.I have never been able to take a 15 minute shower without using up all the hot water.I never had that problem with my old 40 gallon gas heater.Also my shower head plugs up with lime deposits so often that many times i cannot finish 1 shower without taking it apart and rinsing it out.The gas heater did that only 3 or 4 times a year.That makes me very reluctant to use another electric heater even a tank-less.I don't want a water softener.I am willing to put up with cleaning the shower head 3 or 4 times a year.If anyone is using a tank-less now i would like to know what brand it is,how strong it is and how happy they are with it.Thanks!
The first 4 answers seem very knowledgable but it does not sound like you are using one in your home.I need an answer from someone who is actually using one.Do you like it? What size and brand is yours? Can you take a long,hot shower? Gas or electric? What about lime deposits? Thanks!

. So that it gets off automatically after 10 minutes ... Please suggest .
I am located in india
I forget to turnoff power . There is no feature of getting it powerd off when tap is closed.
OR you may assume it as a water heater with tank.

Tankless gas water heater – Cost?

What is the typical cost of buying the equipment and installation of tankless 'Gas' water heater? For my house we need 2 of them.

My house is being constructed right now, so I asked my builder to put this instead of regular tank. They are charging 00 for each unit. I think this is too high and payback time will also be long. Am I right?

Also, any idea about cost of installing hot water circulation system to conserve water. Push of a button will bring the hot water within a minute to the faucet.

Thanks You!
Thanks Eric.

What will be the payback period if I'm replacing tank one with this Tankless Gas Hot water system? If I save a month, then it is more than 10yrs. Seems not worth it. What you guys think.

I have a fairly new natural gas hot water heater but where I'll be using it at has a propane bulk tank. A friend of mine said he heard that the burner has to be changed but we aren't sure about that at all.

My oil-fired baseboard heat furnace (I live in CT) also makes the heat for hot water via a domestic coil. To do this, it stays hot all of the time, 24-7 regardless of temp outside. It's 176,000 BTU and ends up using a full 275gal tank of oil (currently at 4.15/gal) during the summer months. I have accidently hit the emergency switch at night to find no heat the next morning for a shower, but after flipping the switch back on, we have hot water in less than 5 minutes. Is there a way, and is it safe, to shut the beast in the basement off during the night hours (say after 9pm) and have it stay off until a set time or possibly until it detects water flow in the hot water pipe? For that matter, would I be able to have it shut off all the time (in summer of course) and fire up only in on-demand hot water situations? Please ONLY answer if you have valid infomation on my question. Thanks!

We need a new water heater and are very torn between a tank, a tankless gas, and a tankless electric. We're leaning towards the electric. Any advice?

I would like to know the best places to look for a tank less water heater that uses liquid propane gas.

Our hot water was hardly hot this morning. It wasn't cold though. Does this mean it's for sure going out? this is our second in 8 years. Is there something that can be done to maybe fix it or do you just have to replace them?

Also, I might be interested in switching to a water on demand if I have to replace. What's the best price on those and is it easy to switch from the tank kind to an on demand one?

My plumber recommended replacing my 50 gal hot water heater with a wall-mounted instant hot water heater that does not require a tank.
I was wondering if this is recommended, are homeowners generally happy with this product?

Tankless Hot Water System – cost savings?

I am considering changing out our 10 year old electric hot water heater with an electric tankless system... I don't have access to gas/or lp.

The benefits I see are that you only heat the water when you need it, and it doesn't sit in the tank waiting...

The thing I have trouble wrapping my head around is going from tank electric to tankless electric - it seems like a wash - i.e still using electricity.

Is there a significant savings in going to tankless... even if I select an electric tankless system.

i am thinking about saving cost and energy. want to get a tankless water heater. i would like to have a solar water heater too, but heard that u need a stoage tank for the solar heater. not sure if i can combine the two. anyone got an answer for me?

Propane tankless water heater?

I'm building a new house and was thinking about putting a tankless propane water heater in the house. My question is, I'm wondering if I can use a 100lb tank to fuel the heater and how long would it last under normal use? Like for a 117,00 btu heater.

I am looking into pruchasing a tankless water heater but do not want to pay more to operate it than the tank i have now. I know my tank runs on 1000 btu's and most tankless heaters run at about 10 thousand. Is it worth it to switch over?