A friend recently installed a Whirlpool gas hot water heater (7 days ago). He told me the water will go from hot to luke warm after about a minute. I looked at the install and its perfect. I ran the hot water for several minutes and it was fine. Pilot is good and the water is very hot so all 50 gallons isnt running out in less than a minute. I then turned off his recirc pump just as a trouble shooter and went home. He called and said it is still going from hot to luke warm after about a minute. Its a hit or miss thing too, it doesnt happen every time. I am at a loss, anyone have any ideas?

What do you mean by "turned off the circulator"? Did you unplug it or shut the valves at the pump?

there is a recirculating pump plumbed outside the water heater that constantly recirculates the hot water through the hot side pipes so the water is hot as soon as you turn it on. This is code in Arizona because water is like gold here.

IT is NOT code, and there are many more homes without circulators than those with one. But the question was HOW did you turn it off.

is the hot pipe connected to the hot side and cold to cold?

I figured it out. The person who installed the recirc pump did not install a check valve so the cold water was mixing with the hot. Thank you for your help.