Originally Posted by Kimmey1
I have a Noritz tankless hot water heater and when the temperatures are cold my husband has to reset it. Does anyone know what could be the problem.
I expect there's no problem with your water heater, Kimmey. I have exactly the same situation here in Winnipeg. Winnipeg gets it's water from Shoal Lake, which is located about 60 miles south east of Winnipeg. During the summer, the temperature of the cold water that comes into my building is a full 60 degrees F in the summer. During the winter, that temperature will be closer to about 40 degrees F. That is, if you get your water from a river or lake, the water coming into your house will be colder in the winter than in the summer. If you get your water from an underground aquifer, like Phoenix, Arizona, it'll be the same temperature all year round.
What your Noritz tankless hot water heater is telling you is that it takes more energy to heat colder water than it does to heat warmer water. And, that seems to make some kinda horse sense.