I have been tracking an issue we are having with our hot water temp in the morning (showers). I have been testing the hot temp in a sink with the cold supply turned off.
On days that my front irrigation runs the temp seems to drop into the upper 90s which makes for a warm shower. By mid day the temp is up around 115. On days my irrigation does not run, the morning temp is 115+ and holds through the day. I thought of the simple 'they connected my irrigation to my hot water', but the tank is not empty, nor is it trying to heat the water after the irrigation runs, which I would imagine it would if it was just emptied onto my lawn. Plus the irrigation water is not scalding 115+ coming out.
Any thoughts on why this would happen or tests I can run on the hot water heater? Does general water pressure (which drops with the irrigation running) impact the hot water?
I guess it could be random with the irrigation system running and I actually have a hot water thermostat issue, etc. The hot water heaters is only 5 years old.