I am having hot water issues again ... last year when I had similar issues, I was told by people here that the mixing valve is the culprit. when I got it replaced, the issues went away, however, similar problem has now reoccurred. When I am in shower or keep a tap on for a bit long, then the water becomes luke warm.
My furnace utilizes hot water to heat the house, so the hot water tank is performing dual function. Thinking that the mixing valve would have gone bad again, I replaced the mixing valve again (spent approx $250 - parts/labor), but it didn't help! Then I called Reliance as I am renting the HWT from them, and the guy came in and measured the temperature of the water leaving the tank, and it was perfect - so he said not much he can do about it. The tank is working as it should.
I have put the HWT setting to MAX HOT. Some times the water is nice and hot, but then it becomes luke warm and no I am not over using the water to run out the hot water ... it just becomes luke warm in few minutes of turning the hot water tap on.
I am not sure what to do
I am really out of options that I could have thought of - any ideas? Any suggestions would be greatly appreciated.
EDIT: There are two pipes coming out of the HWT. One is hot, and one is cold. The hot pipe is very hot that goes into the mixing valve's (H), which is also connected to the cold water (C) - the mixed side is luke wam most of the time. I have put the mixing valve at full hot.
The Cold water pipe that comes out of (or goes into) the HWT some times is very cold, and some times is very hot.
I showed that to the Reliance guy, and he said it is normal. As soon as you open the hot water tap it will become cold again as the hot water sometimes travel up on the cold water pipe. It didn't sound right to me, but it became cold when the hot water tap was turned on for a bit. As soon as he closed the tap, the pipe became hot again.
Not sure if that is the problem.
PS: I have read both the threads about hot water issues on the main page, and have done most of the things people suggested, but with no luck yet.
This one:
viewtopic.php?f=1&t=58251And This one:
viewtopic.php?f=1&t=58290EDITED on Jan 1, 2014: The problem has been resolved. I called reliance again, and an experienced gentleman showed up this time. He looked at the system, and said the problem is with the hot water pipe that feeds the furnace. He said in these kinds of system most of the time the furnace coil feeds back the cold water via the hot water pipe into the HWT, which causes the water to become luke warm as it is connected right at the spot where the mixing valve is connected. He cut the rubber pipe and installed a "check valve", and immediately the water turned from luke warm to hot again. It has been over two weeks now, and hot water has been fantastic and we've had no problems with it. Problem solved.