I have a fairly new 50 gallon water heater, temp is correctly set in it, a low flow 1.75 gpm showerhead, yet I have to keep adjusting up the hot water every minute or so, then it starts running cool, then out of hot water... all during a 10 minute or less shower. The math says that I should get at least a 25 minute shower before my 50 gallons of hot water is exhausted, given my low flow showerhead... so why am I running out so fast??

It sounds like your dip tube has failed open the link and see how it works, good luck.

John

How a water heater dip tube works and what it looks like. (http://www.masterplumber.net/electricwh/dip_tube.htm)

How could this possibly fail/break on a brand new water heater? Are they that poorly built?

When was this heater installed?

Several things could cause your problem.
1) One of the elements could have failed, as a rule the bottom one. **OR** as john suggested
2) The dip tube could have fallen down in the tank, (see image) causing cold water to mix with the hot.
You ask,
how could this,(dip tube) possibly fail/break on a brand new water heater? Are they that poorly built?
This happens with new water heaters when a inexperienced installer solders, and applies heat directly to the cold water inlet on the tank.
This will melt the plastic flare that secures the dip tube in p-lace and it falls into the tank. John also addressed that when he asked who installed the water heater.
Call the installer back. If he has a problem understanding what's happening one of us will walk him through the repair.
Good luck, Tom

Also, in additon to all the excellent answers above:

1. Make sure your shower head is really 1.75gln/m. In many instances, the flow restrictor is removed during installations. Measure water flow by putting empty 5gln bucket under the head and time it how long it takes to fill it up.
2. With 50gln heater and 1.75gln/m head won't give you 25 minutes of hot shower. I would say you get about 15 minutes. That's because cold water entering the heater during shower mixes with heated water making in less and less hot.
3. If you live in cold climate, turn up your thermostat setting higher in winter and lower in summer.
4. Is your water heater insulated ?
5. Are your hot water pipes insulated between heater and the shower ?
6. If your pipes are not insulated you will loose lots of heat during hot water delivery. This is especially true in winter months.
7. In cold climate, cold water entering heater is ice cold. It mixes with hot water making in lot less hot on impact. Therefore, dip tube is very important to be present and not damaged

I just bought this house in August, the sellers listed the water heater as brand new, just installed, and it looks the part as well.because it came with the house I have no way of knowing who installed it, but the manufacture date of the heater is July 09. Also, I installed the low flow showerhead myself, so I know that is accurate. I do live in east Tennessee, and the weather for the last couple of months has been between 20 and 40 degrees most days should I turn up the temp on the water heater? What is the optimal setting for the temp? It does not have any numbers on the dial, just a hotter -> colder<- setting.

Several things could cause your problem.
1) One of the elements could have failed, as a rule the bottom one. **OR** as john suggested
2) The dip tube could have fallen down in the tank, (see image) causing cold water to mix with the hot.
You ask,
This happens with new water heaters when a inexperienced installer solders, and applies heat directly to the cold water inlet on the tank.
This will melt the plastic flare that secures the dip tube in p-lace and it falls into the tank. John also addressed that when he asked who installed the water heater.
Call the installer back. If he has a problem understanding what's happening one of us will walk him through the repair.
Good luck, Tom


Is this a repair I can do myself? S it possible that one of you can walk me through this procedure, or send me step by step instructions? If so that would be great, as this recent home purchase is putting me in the poorhouse... everything from the hvac to the shingles on the roof have needed replacing, and now this. Thanks a lot for all the great replies/answers.

Locutus,

Please clarify your heater is it gas or electric?
How is hot water in other faucets?
Can you post a picture of your gas valve?

Milo has a good point your gas valve may be not set properly, please reply to my questions and we will go from there, Thanks.

John

Locutus,

Please clarify your heater is it gas or electric?
How is hot water in other faucets?
Can you post a picture of your gas valve?

Milo has a good point your gas valve may be not set properly, please reply to my questions and we will go from there, Thanks.

John

It is electric, there are 2 pipes coming out of the wall above down to the heater, and one coming from the floor up to the top, very close to the side. That pipe has a relief vave where it goes into the heater. The hot water seems fine in other parts of the house, but I have not run it for extended periods like a shower, so as far as I know it would run out in other places too if run long enough. I will add that the heater is just on the other side of the shower wall, so the water only travels about 3 feet maximum from heater to shower.

is this a repair I can do myself? S it possible that one of you can walk me through this procedure, or send me step by step instructions? If so that would be great, as this recent home purchase is putting me in the poorhouse... everything from the hvac to the shingles on the roof have needed replacing, and now this. Thanks a lot for all the great replies/answers.
Any one of us will be e glad to walk you through checking and changing a dip tube. You do understand the function of a dip tube and what happens when one fails don't you?

the hot water seems fine in other parts of the house, but I have not run it for extended periods like a shower, so as far as I know it would run out in other places too if run long enough. Check that and let me know.
To check a dip tube you must shut the water off to the heater and cut and remove the threaded fitting that screws into the cold water inlet, If the dip tube's intact you will find it hanging by a flare in the plastic tube. If there's not a white plastic flare then the tube has fallen off into the tank and must be replaced. ( The old tube may be left inside the tank when you reinstall.
The question has been asked. "Who installed tour water heater?" Was it a licensed plumber? A handiman? Yourself?
Please answer. Tom

Now I would concentrate on element first as Tom suggested, first turn of the power to the heater open the boxes check for any loose connection, to check the resistance it you would need a muleteer, if you haven't done any electric work before I would suggest to call an expert.

You say your heater is new it still should be under warranty find out from seller where did he get it from and call them to come and fix it for you, good luck.

John

The question has been asked. "Who installed tour water heater?" Was it a licensed plumber? a handiman? Yourself?
Please answer. Tom

I had already stated I do nortknow who installed, or where it was bought. The people I bought this house from were complete strangers, I only met them at the closing, everything else was handled by realtors, so I have no way of asking them about this. It was suggested I remove the water inlet to check on the dip tube, which of the 3 pipes I previously described is the inlet? As far as the lower element, if the dip tube is intact that leaves that as the only possibility, so I could just cut the power to the heater and change that out and see what happens after that, if you could provide some instruction for me. I am pretty handy if I have steps to follow. Thanks for all the help, you guys are great!

I agree with Tom: your heater could be running on one element only. Elements are relatively inexpensive and easy to install. Take a picture of the sticker on the heater that shows what kind of element you have. Take it to the local plumbing supply store and buy new one(s). Don't forget to buy Element Socket Wrench. It is a dedicated tool that removes old element in a snap - and install it. If you don't know how - come back, we will lead you through it. Good luck. Milo

I could just cut the power to the heater and go ahead and change that out and see what happens after that, if you could provide some instruction for me. I am pretty handy if i have steps to follow. Rather then drain the tank and perhaps replace a working element let's check it first.
You must understand how a hot water heater works. Water enters and is directed to the bottom by a plastic "dip tube" where it's heated by the lower element. It then raises to the top and the upper element kicks in and maintains the heat. When you make a draw the process starts all over again. With a bad lower element the top few gallons are being heated and when you draw those fer gallons off you get cold water because that's all that's left. Little clearer now?
Let's check that hard working lower element. First turn the heater off AT THE BREAKER BOX NOT THE WALL SWITCH. Disconnect one wire from the element and check across the poles with a resistance checker. You should get a reading on the lowest setting, if not replace it. Now as for changing one. With the electricity still off, turn off the cold water supply to the heater and open the nearest hot water faucet faucet to prevent air lock. Now attach a hose to the boiler drain located at the bottom of the tank and drain the tank. If your in a basemrnt drain into a lower floor drain. You already have the inspection p-lates off so after the tank drains we are ready to remove the faulty element. There are two types, flange and screw in. The flange type just take a socket wrench to remove. THe screw type has a large hex nut built in, if you don't have a wrench big enough they sell a element wrench at your local hardware store. Replace with the same type and the same wattage. I use gasket cement when I install the flang type and wrap the threads with teflon tape on the screw in. After you install the element, with the hot water faucet still open turn on the cold water supply. DO NOT TURN ON THE ELECTRICITY YET!! After, AND ONLY AFTER, you grt a full stream out of the hot water faucet can you shut it off and turn on the electricity. Put the inspection plates on, wait a 1/2 hour and jump into a hot shower. If the element checks out we'll get into the more difficult task of checking the dip tube. Hang in there!
Hope this helps and thank you for rating my reply, Tom

Rather then drain the tank and perhaps replace a working element let's check it first.
You must understand how a hot water heater works. Water enters and is directed to the bottom by a plastic "dip tube" where it's heated by the lower element. It then raises to the top and the upper element kicks in and maintains the heat. When you make a draw the process starts all over again. With a bad lower element the top few gallons are being heated and when you draw those fer gallons off you get cold water because that's all that's left. Little clearer now?
Let's check that hard working lower element. First turn the heater off AT THE BREAKER BOX NOT THE WALL SWITCH. Disconnect one wire from the element and check across the poles with a resistance checker. You should get a reading on the lowest setting, if not replace it. Now as for changing one. With the electricity still off, turn off the cold water supply to the heater and open the nearest hot water faucet faucet to prevent air lock. Now attach a hose to the boiler drain located at the bottom of the tank and drain the tank. If your in a basemrnt drain into a lower floor drain. You already have the inspection p-lates off so after the tank drains we are ready to remove the faulty element. There are two types, flange and screw in. The flange type just take a socket wrench to remove. THe screw type has a large hex nut built in, if you don't have a wrench big enough they sell a element wrench at your local hardware store. Replace with the same type and the same wattage. I use gasket cement when I install the flang type and wrap the threads with teflon tape on the screw in. After you install the element, with the hot water faucet still open turn on the cold water supply. DO NOT TURN ON THE ELECTRICITY YET!!! After, AND ONLY AFTER, you grt a full stream out of the hot water faucet can you shut it off and turn on the electricity. Put the inspection plates on, wait a 1/2 hour and jump into a hot shower. If the element checks out we'll get into the more difficult task of checking the dip tube. Hang in there!
Hope this helps and thank you for rating my reply, Tom

OK, I will try this next weekend when I have a off day (I work 5a to 5p the next 7 days) and let you know, if it doesn't help we can do the dip tube. Thanks for this great info, it is much appreciated.

One more detail: most elec. Hot water heaters have thermostat at each element. You have to set BOTH of them. Not just one. Make sure they are not set too low. Set them both to 125 F.

One more details: most elec. hot water heaters have thermostat at each element. You have to set BOTH of them. Not just one. Make sure they are not set too low. Set them both to 125 F.


I did not know about the lower thermostat... it was turned all the way down to the "a" I just set it up equal to the upper one ( I don't have any degrees on them, just a, b c and d. I have both set just below the "b") we will see if that helps. Thanks!

I think A is the lowest setting. If your thermostats are set to B than they are set too low. That may have been the problem... Adjust them both. Lets see if it helps.

I suggest that during winter time both of your thermostats are set to C... maybe even to C+. Experiment with it yourself. See which setting will give you enough hot water.

I believe Milo resolved your problem and make sure to set both the upper and lower thermostat at the same setting, see the following chart, good luck.

John

TEMPERATURE SETTINGS
HOT - Is a thermostat setting of approximately 120° F,
Which will supply hot water at the most?
Economical temperatures..
A - Is a thermostat setting of approximately 130° F.
B - Is a thermostat setting of approximately 140° F.
C - Is a thermostat setting of approximately 150° F.
VERY HOT - Is a thermostat setting of approximately 160° F.
It is recommended that the dial be set lower
When ever possible.

I believe Milo resolved your problem and make sure to set both the upper and lower thermostat at the same setting, see the following chart, good luck.

John

TEMPERATURE SETTINGS
HOT - Is a thermostat setting of approximately 120° F,
Which will supply hot water at the most?
Economical temperatures..
A - Is a thermostat setting of approximately 130° F.
B - Is a thermostat setting of approximately 140° F.
C - Is a thermostat setting of approximately 150° F.
VERY HOT - Is a thermostat setting of approximately 160° F.
It is recommended that the dial be set lower
When ever possible.

Just took a 15 minute shower, and the water temp remained constant the whole time, no adjusting up as before. I believe the t-stat setting did the trick. Thanks Milo & John for troubleshooting this and coming up with the correct diagnosis. You guys are great!

Great ! Glad we were able to solve your hot water delivery problem ! Good luck to you and stop by next time you have another question ! Milo

Thanks for the update and it is our pleasure to help.

Regards,
John