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 Posted: Wed Jan 26th, 2011 07:44 pm
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tsenti0671
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I got a brand new whirlpool 40 gallon gas water heater in aug & it has never worked right. It runs out of hot water w/in 10 minutes and while I am in the shower, in order to keep the water hot, I constantly have to turn my cold water down. I have the temp turned up pretty close to teh highest temp it will go to. Whirlpool thought it was a gas valve, I had that replaced and it didn't fix the problem. They sent a plumber, he said the water heater appeared to be working fine. I had the dip tube checked, it was also fine. So, whirlpool replaced my water heater. Just 2 days ago I got a brand new water heater professionally installed and it did not solve the problem. I belive the odds of getting 2 bad brand new water heaters is pretty high so now I believe there is a problem with my pipes or my gas lines. Has anyone heard of this? I have asked a million people and they all are shaking their heads.

And just as an FYI, on the water heater that I had before I got the original new water heater in Aug, I didn't have the exact same problem, but i DID always have to have the temp turned up very high to get enough hot water for 2 people to take a shower.

Someone please help!!

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 Posted: Wed Jan 26th, 2011 10:22 pm
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energyexpert
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What is the BTU input rate and EF of your new WH?  What was the size, BTU input rate, and EF of your old WH?  What is the shower flow rate?

If inlet water is 40F and outlet is 120F and HW flow is 3 gpm, you need 2000 BTUs/minute input to keep up.  A WH with 50,000 BTU/hour input with 20% flue loss only adds 667 BTUs/minute.

David


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 Posted: Wed Jan 26th, 2011 10:46 pm
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tsenti0671
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BTU input rate is 40000. The old one was 20000, so the one I have now is even better. Size on both was 40 gallon. I have no idea what an EF is. My water flow is 2gpm and at that flow my water temperature should not drop more than 30degrees for 14 minutes but it drops in 7.

Thanks for your help, but the second sentence of your reply is like a foreign language to me. I hate to say this, but I'm a clueless girl. I only know what I was able to tell you because whirlpool has made me jump through a lot of hoops and do a lot of tests to try and troubleshoot.

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 Posted: Thu Jan 27th, 2011 02:21 am
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ROCKO
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Have you checked the plumming? Is the house fairly new? We sort of had that problem with our newly built home. Turns out the plummer goofed when doing his work and connected cold to hot in a spot. Its' worth a shot.

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 Posted: Thu Jan 27th, 2011 02:35 am
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elenano
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Especially because this is a replacement, you should think about cross connections. There is a Tanklet about this, by the same name, that you can reach from a link at the top of the topics page. There is a simple test you can make. Do it and report back.

It's also not impossible that the new heater lacks a dip tube or has a damaged one.

Randy Schuyler

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 Posted: Thu Jan 27th, 2011 03:42 pm
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tsenti0671
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I am pretty sure that there is still water dripping out of the hot water faucet even when the water is turned off. I have had the water turned off about 4 times in the past month and, although I wasn't paying 100% attention, I do slightly remember that the water never stopped dripping. I will do the test again this evening when I get home just to be 100%. So the question is - what if there is a cross connection...what then?

Also, to Rocko - it's a condo, built in 1970, so not new by any means, but thanks for the suggestion!!

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 Posted: Thu Jan 27th, 2011 04:25 pm
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elenano
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The Tanklet is full of examples. But it means cold water can get into the hot side or vice versa.

Randy Schuyler

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 Posted: Thu Jan 27th, 2011 08:46 pm
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energyexpert
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Tsenti0671,

For starters don't put yourself down; you are not clueless.  Clueless people would not find a website and ask questions.

My second sentence merely points out that most residential tank water heaters will not make hot water as fast as it is being used.  Some people don't understand why their 5 gpm shower turns cold in 10 minutes.

EF is Energy Factor.  It sort of relates to efficiency.  Gas WHs have EFs of 0.55 to 0.8, electric WHs have EFs of 0.88 to 0.95, and heat pump WHs  have EFs of 2.0 to 2.5.

Someone posted not long ago who had changed out the WH several times and finally found a hot water leak under the slab was his problem.  If both your inlet and outlet pipes connect to the top of the WH, both lines should be about the same temperature (without heat traps) 30 minutes with no hot water usage.  If the cold is still cold after 30 minutes it indicates you have flow through the WH.

David

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 Posted: Thu Jan 27th, 2011 09:59 pm
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tsenti0671
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Ok, I was wrong. I turned off the water supply to the water heater ONLY, not to my whole house, just the water heater, that's what I was supposed to do right? I then went to all of the sinks and the shower & opened the hot water side and it DID stop running, all of them. So this rules out cross connection right?

I want to say that I don't believe it is the dip tube because I had the dip tube on the old water heater that I had 6 days ago and it was fine, but I was having problems.

Suggestions? Am I just doomed to 7 min showers? 

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 Posted: Fri Jan 28th, 2011 06:18 am
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eleent
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Hello:  It sounds like it isn't a cross connection.  That's good!  Two other things come to mind.  Is there a recirculation line?  This is supposed to give you quick hot water, but sometimes water can flow backwards through it.  A second possibility is that the hot and cold lines have been hooked up backwards,  (yes, I've seen this a number of times).  Another possible dip tube problem is that there is none in the heater at all.  So, run a little hot water and feel the pipes.  The incoming cold line should get cold.  It should go to the port on the heater marked cold.  If this is all correct, next is to undo the cold inlet and see if there really is a dip tube there.  Do turn off the water first or get soaked :shock:  Do let us know what you find.  There is a solution!

Yours,  Larry

ps.  Possibility number three.  A high flow shower head could cause this.  Take a bucket and catch 30 seconds of flow from the shower.  Double it to get gpm (gallons per minute) flow.
pps.  The 1,000,001 (or 1,000,002) person likely has the answer :cool:

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 Posted: Fri Jan 28th, 2011 10:04 pm
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tsenti0671
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Ok, I ran the hot water and the cold water pipe got really cold. Also, the hot and cold lines are hooked up correctly. I have to have someone else undo the line to check and see if the dip tube is in there. I will try to have that done this weekend.

My gpm is 2, so that's normal.  

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 Posted: Sat Jan 29th, 2011 04:14 pm
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eleent
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Hello:  One more test ;)  When you are getting cool water from the shower, go around and run other taps in the house one at a time to see if they run hotter than the shower.  If so, it points to a shower valve adjustment/problem.

Yours,  Larry

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 Posted: Mon Jan 31st, 2011 01:35 pm
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tsenti0671
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Did the latest test last night. Shower ran out of hot, then I went and checked all of the other taps and they are all cold. So it's not just the shower. So, now what? :?

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 Posted: Mon Jan 31st, 2011 10:32 pm
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eleent
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Hello:  We're narrowing it down :cool:   Did you get a chance to check and see if there is (or isn't) a dip tube where it should be ... and is there a recirculation line?

Yours,  Larry

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 Posted: Mon Jan 31st, 2011 10:42 pm
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tsenti0671
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Not yet. My condo association manager is coming over toinght to check on the recirculation line since I dont' really know what that is and he knows how these condo's are 'put together'. I'll have to call a plumber to check the dip tube because I can't do it myself and I was kind of waiting for the condo guy to come first. So I'll report back when I get all of that done. Although, if I'm calling a plumber over to check the dip tube, I'm just going to have him help me figure it all out, so hopefully I will be reporting back that the problem is solved. Thanks so much for all of your help. I wish I could do some of this stuff myself so I don't have to call a plumber.

Oh and I'm in the path of the huge midwest snowstorm so I probably won't be able to get a plumber here for a couple of days. But I will be sure to post back as soon as I can.

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 Posted: Fri Feb 11th, 2011 04:59 pm
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tsenti0671
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Hello all, it's been a couple weeks and a few things have happened...

1. I had my condo manager come out and he tested the pressure of the water coming into my condo, it is 100psi. he says it should be around 60-80. He thinks that the water is coming into the water heater w/ so much force that the cold and hot water are mixing inside. Does this sound possible? He suggested that I get a pressure reducing valve put on the cold water pipe going into the water heater.

2. I had a plumber come. Dip tube is fine. Everything with the water heater is fine. There is no cross connection, no recirculation line. He tested the water pressure coming out of my shower head and said it is 5gpm. So we put on a new shower head that only lets out 3gpm. That only got me an additional 2 minutes of hot water, so now I'm at 9 minutes.

The plumber suggested that I could reduce the water pressure even further by putting a pressure regulator in the shower head (in lieu of the pressure reducer on the cold water pipe), but i'm thinking that will only gain me another minute or two. I still don't think 10 minutes of hot water is right. There HAS to be something else wrong.

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 Posted: Fri Feb 11th, 2011 05:09 pm
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elenano
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You definitely need the pressure reducer on incoming water. Anything over 80 psi is very hard on all the plumbing and appliances. You may need an expansion tank, too, to prevent thermal expansion spikes.

Randy Schuyler

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 Posted: Fri Feb 11th, 2011 05:15 pm
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tsenti0671
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Randy, 2 questions...

1. Do I need the pressure reducer on incoming water only because it is hard on all plumbing or do you think that will help w/ the hot water problem I am having?

2 Wouldn't you think that if I am having this problem because of the pressure of my incoming water that the entire condo complex would be having the same issue? I'm just asking because it seems odd to me that I am the only one having this issue.

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 Posted: Fri Feb 11th, 2011 08:42 pm
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elenano
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Mainly the first reason. You're right, though, that if you have high pressure, they should, too. As to the primary problem, Larry was well along with that, and he knows more than I do. I think I should leave it to him.

Randy Schuyler

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 Posted: Sat Feb 12th, 2011 05:12 am
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eleent
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Hello:  Regardless of the pressure, cold water can only flow into the tank as fast as hot water leaves it.  As long as the dip tube is good, you should get 70 to 75% of the volume of the tank as undiluted hot water.  That's about 30 gallons. 

Next thing to think about is temperature.  If your heater put out 105 or 110 degree water, you would not mix much if any cold in at the shower.  At three gpm, you would get a ten minute shower. 

Really cold incoming water can make for shorter showers in winter and spring than you get other times of the year.    I'd actually measure cold water and hot water temps by running a cup full and sticking a candy or meat thermometer in it.  With this info you 'll be able to figure just how long a shower you really should get.  (we can help with that math) ;)

One more test is to fill up a five gallon bucket from the tub spout repeatedly and quickly with hot water until the water from the spout starts to cool.  This test gives you the actual volume of undiluted hot water and eliminates much guesswork.  Water does weigh about 7.5 pounds per gallon.  A smaller container might be less trouble to handle.

Do let us know what you find. 

Yours,  Larry

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