constant running

I have a less than 2 year old, builder installed Navien water heater that has decided to be in a constant post-purge when it is not being used. The status alternates between POST-PURGE AND DHW-WAIT. I noticed this about a week ago as I heard a vibration upstairs and it was the water heater...

Hey All, I have two issues but gonna start out with my setup description. I am no plumber of course, I am a capable homeowner. I was quoted $4700 for an RO system for my home and decided that I could definitely build my own. So..... $900 later, whole house RO. Was doing great for the last 4...