The last two days I have gone to take a shower and there is very little warm water, then it is cold. When my wife gets up an hour or so later, there is hot water and it appears to be present throughout the day. I looked and the pilot was lit and the heater was warm to the touch around the pilot.

Verify and check whether your thermostart is working or not, otherwise call your plumber.

Hi,

I really agree with SpaParts. You have to check water heater by plumber.

Hope helps you!