It is concerning to think you have a water heater problem. For the most part, a water heater is an expensive proposition, no matter if it is a repair or replacement. I had a customer call to ask about a problem he was having with the water coming from the hot side of all faucets in the house. The water coming from the hot side of each faucet was cloudy or milky. Naturally, since the problem is occurring at all faucets, you would consider the water heater to be the problem.
As it turns out, lots of people have milky or cloudy hot water. Water is under pressure which causes any air in the water to dissolve until the pressure is released at the faucet. Air is introduced in the system in a variety of ways from groundwater to the distribution system. If you have a lot of dissolved air in the system when the pressure is released at the faucet, you will get a milky appearance in the water. But watch it closely; the cloudiness will disappear as the air escapes. You will see the water clear in a few minutes from the bottom of the glass first (since the air rises). This is harmless and isn’t a health concern.