I got a service call for no hot water pressure today. I check the heater if a valve was shutoff but they were open I felt the pipe on hot side and before the valve it was hot but after the valve it was cold . So I thought amybe sediment clogged the valve so I changed the valve and nothing that wasn't the problem . I tried causing a hammer lock by releasing all the water from the heater with both valves closed then open the cold side to fill the water back up and then once its filled I opened the hot side to get a burst of air to maybe clear sediment possibly causing a block but all to no luck cause nothing happen I still got no water pressure on hot side can anybody help please thank u

How old is the water heater, and is it gas or electric?
How is the weather hope it is not freezing?
I am not getting, what do you mean by hammer lock?
Did you try to open the heater drain at the bottom of the heater and drain the water or what?

Do this leave the cold valve open, connect a garden hose to the drain at the bottom of the heater, open a hot side of the faucet inside the house close to the heater, move the hose to a safe area open the drain, and open the T&P valve see if you have a strong stream of water, if you have good flow, close the T&P valve, close the cold valve and close the drain at the bottom of the heater, remove the garden hose, and disconnect the hot line, check the nipple for any dirt and clog if you see any thing remove the nipple clean and install the nipple, connect the hot line and turn on the water (open the cold valve) see what happens, hope it will help, if no water from the hot side get back to us, Thanks.

John

I felt the pipe on hot side and before the valve it was hot but after the valve it was cold . Are you saying that you have a shut off valve on the discharge (Hot) side of the water heater? This is against code and outlawed in my area. Regards, Tom