Two year old GE hot water tank suddenly doesn't have enough hot water

[nekoian]

We purchased a GE (made by Rheem) 50 Gallon Gas tank (12 year warranty) from Home Depot about 2 years ago. It has been working fine but last weekend I ran out of hot water in the shower after my wife's shower. Last night my son had a medium length shower and I went to draw a bath for my daughter and the water was cold 1/2 way through. No other appliances had been running recently either time.

I flushed the tank last night. My wife said she ran out of water by the end of her shower this morning after me.

I'm suspecting maybe the dip tube? Why would it crack or break on such a young hot water tank?

The flame looks fine, mostly blue. Temp setting hasn't changed. No sediment was found during flush. I checked the water meter and there doesn't appear to be any leaks.

[jimbo]

Well, since this apparently happened all of sudden, it is very possibly due to a leak somewhere, or a failure in a recirc system if you have one..

NOW, you should know that by "rule of thumb" a 50 gallon heater will deliver approx. 35 gallons of water at suitable shower temperature. A 'medium long' shower will use up most of that, leaving little for that tub! And this situation is based on some assumptions: heater set at ~125 degrees, ground water ~55 degrees, so it will vary in the winter.

Certainly the dip tube would cause that. This is not a common problem, but is fairly quick to check.

[nekoian]

I thought about the winter water but we never ran out of water last winter. I mean *never*. Now it seems very frequent. I checked to see if the water meter was moving at all with nothing going and it's not.

I found a youtube video that talked about timing when the heater turns on after you start opening hot water faucets. His tank registered over a minute before the heater turned itself on which indicated a bad dip tube. I'm going to try that tonight.

[Gary Swart]

Several years ago, there was a lot of failed dip tubes. A manufacturer that provided dip tubes for several brand of cold water heaters used some faulty materials that cause the tubes to fall apart. This problem was fixed and the problem went away. That is not to say that a dip tube still can't fail. The are easy to check and easy to replace if necessary. They are located directly under the nipple in the intake. Just remove the nipple and you can fish the tube out with your finger. They should extend clear to the bottom of the tank. If it does, then the dip tube is not your problem. If it is broken off, then just get a new tube, cut it to length if necessary, slip it in, and replace the nipple. May not be the problem, but it's so easy to check, it's what I'd look at first.

[hj]

Unless the heater was over 10 years old, it is NOT a dip tube issue. However, I had exactly the same problem with a customer this week and his problem was a defective shower valve balancing spool which was mixing "a lot" of cold water with the hot, so he only had "warm" water even though the heater was up to temperature.

[jadnashua]

FWIW, gas WH come with different sized burners, so one 50-gallon tank may not be the same as another, even from the same manufacturer - it all depends on the model.

[nekoian]

So I timed how long it took for the burner to come on with two hot water taps running. 35 seconds. Seems too long to me.

[jimbo]

So I timed how long it took for the burner to come on with two hot water taps running. 35 seconds. Seems too long to me.

I have never seen this test recommended by a manufacturer. I don't think all the parameters..incoming temp, heater setting, piping, GPM of taps, etc,....are well enough controlled to make a meaningfull interpretation of "35 seconds". You can settle the dip tube by simply disconnecting the cold water inlet and removing the nipple. Find out from your manufacturer ( Rheem, your 12 year is essentially the Fury 42VR50 series) if the dip tupe is "drop in" or integral with the cold nipple.
Again,, nothing is impossible, but the "bad dip tube era" was 1992/1993. Since that was fixed, dip tubes are rarely on the radar. Lets stop guessing and get some answers.

[MACPLUMB 777]

Unless the heater was over 10 years old, it is NOT a dip tube issue. However, I had exactly the same problem with a customer this week and his problem was a defective shower valve balancing spool which was mixing "a lot" of cold water with the hot, so he only had "warm" water even though the heater was up to temperature.

I have fixed this the same way ! you have a single handle valve that is mixing cold like
hj posted, in the old days Moen fixtures were famous for doing this !
now with pressure balancing spools then that is your problem forget about water heater

[Hackneyplumbing]

We purchased a GE (made by Rheem) 50 Gallon Gas tank (12 year warranty) from Home Depot about 2 years ago. It has been working fine but last weekend I ran out of hot water in the shower after my wife's shower. Last night my son had a medium length shower and I went to draw a bath for my daughter and the water was cold 1/2 way through. No other appliances had been running recently either time.

I flushed the tank last night. My wife said she ran out of water by the end of her shower this morning after me.

I'm suspecting maybe the dip tube? Why would it crack or break on such a young hot water tank?

The flame looks fine, mostly blue. Temp setting hasn't changed. No sediment was found during flush. I checked the water meter and there doesn't appear to be any leaks.

First check for a hot water leak. If no leak is detected perform a draw test. Both test could be done in under 30 minutes.