Leaking via Backflow Preventer
I have a Bradford White MIITW75T6EN12 water heater that has recently started leaking cold water out of the backflow preventer. I felt both the pressure release pipe and the backflow pipe, only the backflow was wet.
Back in winter we had a mixing valve installed so we could supply hotter water to the basement radiant heat system but still keep temperatures at 120 for the kitchen sink.
First image is from the side at the blackflow preventer, second is the mixing valve installation. On the side is an Amtrol Term X-Trol ST5 expansion tank. Home was built in 2002 and we purchased Fall 08.
No changes or adjustments have been made since the mixing valve was installed and temperature on the heater turned up. This leak started about a week ago, I'm down in the basement at least 5 times a week for excercise and walk by the heater and softener each time to get to the "gym"
Cause for concern? Warmer weather in general playing a role here?