I'm at a quandry of what to do?? About once a month or about every 15 showers the hot water stops... there is Nothing I've done to prompt it.... like about 5 minutes into the Normal Regular, Nothing Different Shower, the Hot water stops and cold water starts!!! The next time I use the shower, there is nothing amiss in it's function. I've only showered in one location that its happened in... ie. don't shower much in the other shower in the house and it never happened there. Also it takes it near 2 minutes for the water to get hot it the very beginning, but I've had that explained that there is alot of pipe footage to travel and it takes a long time.... However, the distance is not 5 foot longer than using the hot water heaters of the past that Ive ever had in this house and I've lived in for 37 years. Thanks for an explanation, or suggested action I might take to improve my experience with the Tankless Water Heater.