I have a large master bath that has a large Jacuzzi tub and a large walk in shower all with 3/4 inlet supply copper. I have installed 2 new 50 gallon gas heaters with the highest BTU possible in parallel in the attic directly above the bathroom. The old heaters seemed to supply enough hot water to fill the jacuzzi and take a hot shower until they rusted out and began leaking. The new heaters do not supply enough hot water to even fill the jacuzzi halfway. The shower is lukewarm or cool.

You should not come up short with 2 heaters this size. Are the heaters gas or electric and what temp are they set? You said in parallel but just checking, does the first tank hot feed into the second tanks intake?

They are both 50 gallon, G.E. gas. They are 40,000 BTU. We ran them parallel. They both feed at the same time into a 3/4 inch copper line. I have the temperature set at "very hot". I checked it again today Wednsday and both units fill the jacuzzi with 120 degrees water (dangerous temp) with only the hot water valve open. They fill to about 1/3 full then the water temp quickly begins dropping to 85 degrees within 5 minutes. I checked the in/out supply lines and sure enough, they were both doing the same thing. The hot side was cooling down and the cold side was cold and both flames come on and re-heat the tanks for about 45 minutes. It is as if the cold water supply into the tanks is overpowering whatever hot water is there. There is not even 30 gallons of hot water between the two of them! Is it a design flaw? How could it be a dip tube problem in new heaters? I'm stumped! Thanks for the feedback.


Also, could this be a GAS problem? Do I have enough flame heating the water?

Is this the way your water heaters are installed ?

Did someone remove the dip tubes? Or did they install the copper adaptors to the tank before sweating the tubing to them and melt the dip tubes off? I can't think of a gas problem that would cause what you describe.

Yes your diagram is accurate. It is what I call "parallel" as opposed to "series", where one tank feeds the other. We used the flex stainless supply lines on a 3/4 short nipple. No sweating. Is is possible to replace the dip tubes? If I can't figure it out I may have to install tankless heater$!

Make absoluely sure that the hots are plumbed together and the colds are together. If a hot and cold were reversed, you might get that sort of problem or if the dip tube was in the wrong side or not installed.

Yes, the dip tubes are replaceable.

Do the following. Turn off the water to heater #1 and do your test. Then turn heater #2 on with heate #1 off and do the same test.

If the results are significantly different then the issues I suggested are possible reasons.

If the set up's correct then with gas hot water heaters about the only thing that would cause this problem are the dip tubes. Pull the cold water supplies and check. Let us know what you find. Good luck, Tom

What is the size of your gas line feeding these 2 water heaters?

Is this gas line going directly from the gas meter to the heaters or is it branched off from your house gas system ?

Since there were two older heaters in place dooing the job I think we might assume gas supply is good. How did the install and di he solder the connections at the top of the heaters?

Thanks to all. I agree that it can only be the dip tubes. I have tested each heater individually with the same results. I have also noted that as the hot water filling the tub began to cool, I quickly checked the hot/cold supply lines and they were identical in temperature with a "warm" hot side and the cold side unchanged. I thought maybe there was not enough gas pressure to the flame so it might not be hot enough, but it is heating the first few gallons of each heater to 120 degrees! I will check the dip tubes.

A few of us mentioned earlier that some installers get their torch too close to the top fitting and melt the tube.

Love the pic Milo. Why is the drawing showing hots on the right and colds on the left?

Love the pic Milo. Why is the drawing showing hots on the right and colds on the left?

That's from the back. :D

I hope #13and #14 are both kidding, Merry Christmas to you all.

Bob

Yes Bob, just having some fun. And Merry Christmas to you too.

Good Catch MGD77 ! LOL ! You are looking at it through a mirror ! LOL !

Of course, they cold should on the right and hot on the left.

Just having fun here too. Merry Christmas all.

OK! Today I pulled and checked the dip tube in one heater. It was fine. It was only about 30 inches long (about 1/2 way into the heater. It had a spiral baffle at the end to "swirl" the water. Bothe heater were made in 2008 and installed in 2009. Now What? The owner wants it fixed and he wants G.E. to make them right. What can I tell them? There is nothing wrong. They just don't work! The water is getting hot enough that the Cold side is even hot until I turn on the hot water in the tub. They both simply run out of hot water too fast!

I am seeing a TON of consumer complaints about G.E. customer service!

I think you got short changed in the DIP tube department. 1/2 the heater isn't enough. Time to go above GE for complaints, meanwhile I think you need a longer tube.

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

Length of dip tube? - Self Help Forums (http://www.selfhelpforums.com/showthread.php?t=8412)

Cut to length DIP tube
Law Supply - Water Heate Parts and Accesories (http://www.lawsupply.net/heaters/water_heater_parts/index.htm)

That dip tube being only half way down the heater is not enough. Admittedly, I have only pulled a few dip tubes, but they should go almost to the bottom. That swirl action is to get the water moving around the heat source so that it all heats evenly. I don't use GE water heaters so I can't speak to customer service.

Sorry, I didn't see post #21. My browser dropped me on the second page.