Hello! We first started noticing problems with our hot water before Christmas. It would start hot and gradually keep getting cooler. I kept having to adjust the temperature, then it got worse until it was almost no hot water.
We replaced both elements and thermostat with a generic kit from HD. For a few months after that, the water was great. Now it seems to be doing the same thing again. The heater is about 5-6 years old - electric, Rheem.
Does ti sound like something else is wrong or should we not have used a generic kit?
Thank you

The first thing I would check are the elements. If they check out the next thing to check is the dip tube. If either were faulty it would give you the symptoms that you have. More questions? I'm as close as a click. Tom

Tom is right on.

The dip tube brings cold water to bottom of heater and is heated by bottom element. As water is used upper element reheats water.

If the dip tube is broken or has disconnected from input, cold water will not have enough time to heat up.

Chuck

I agree that a broken dip tube could cause this problem. However, since replacing the elements and thermostat fixed the issue I am thinking there may be muiltiple issues going on. Chances are good a bad element was your first problem. However, now that the problem is back, you need to start investigating all over. Test the elements, top and bottom for 240 vac. If you find both are heating while you are getting cold water then its is time to open the dip tube on the top of the heater.

you need to start investigating all over. Test the elements, top and bottom for 240 vac. If you find both are heating while you are getting cold water then its is time to open the dip tube on the top of the heater.
Solid advice from Bob and Chuck. Let me take it a bit farther. A dip tube(see image) is a plastic tube in your water heater that directs the incoming cold water past the hot water in the upper part of the tank down to the bottom where it will be heated and raise to the top.It's located under the large hex nut on top of the tank Unscrew the nut and check the tube to sse if it's still intact. Good luck, Tom

Make sure to clean as much sediment as you can off the bottom of the tank so the bottom element is not sitting in sediment. If you didn't do that before the bottom element is probably done for.