Water Heaters - Low hot water pressure - all faucets?

I just installed a new 50 gl Whirlpool electric water heater on 11/11. The old one had started leaking after 18 years. Everything went OK on the install, and for a whole day afterwards. Starting the evening of 11/12, my water pressure on the HOT side only, has been dramatically reduced :mad: ? I have checked both gate valves going to the heater, both are fully open; the hot water side was fine for a whole day after installing. I took off all the Aerators on the faucets just to make sure they weren't clogged; still low pressure on hot side only. I had replaced all the galvanized pipes in the house with copper lines about 6 years ago. I also put 2 new copper flexible supply lines there @ the water heater. One of them twisted a little more than I wanted, but it didn't crimp it closed, not even half way. Am I overlooking something, or what could possible be the problem?
Thanks in advance for any ideas/help!!

Rob

Rob,
Sounds like you've eliminated all the usual suspects.
The next thing that I can think of would be to turn off the main, drain off the pressure a bit, and take the water heater cold water supply gate valve apart to check it. It may be clogged with old debris, or something may be wrong with the gate even though all appears to be normal.
Post back on this same thread and let us know what you find.
Good Luck!
Mike

While you have it shut down you may just as well check the gate on the hot water line too. At least you'll have one more thing that is eliminated as a cause. Gates can snap off and the handle still feels normal, just not doing anything inside the valve. Good luck and post back.

I would also suspect a defective gate valve. Best to replace with a full-flow ball valve.

Hi, been awhile since I originally posted this question. I am still having low water pressure just on hot water side (all faucets), but had one more question. I am getting ready to replace the last of the galvanized pipe in the house (just two sections that go to the kitchen), and get rid of the hot water side gate valve, and replace the other w/ the ball valve as recommended; BUT my electric bill has more than doubled the past couple of months since I replaced the heater. I called and complained to the electric company, they say it is an accurate reading from the meter. This is the only thing I changed in the entire house, been there for over 10 years, and the bill has NEVER been this high! Could the low HOT water pressure be causing the heater to "run" more than usual, or what could cause an unusually high electric bill (especially w/ it being a new heater!). Thanks!!!