Consider that if you live in the southern united states your groundwater might be 65 to 70 degrees while if you live in the north like minnesota wisconsin canada your groundwater may be only 40 degrees.
Tankless water heater water temperature.
Maintaining constant shower temperature.
If we set temperature of water heater at 120 f it will burn less gas or fuel or consume less electricity.
This way it leads to emit fewer greenhouse gases which helps us to save our environment.
Similarly unlike with a tank heater the hot water temperature from a non modulated tankless heater is inversely proportional to the rate of the water flow the faster the flow the less time the water spends in the heating element being heated.
Florida and minnesota will not have the same groundwater temperature.
Mixing hot and cold water to the right temperature from.
This is a very important factor in the type of tankless heater you buy.
If you believe that this might be the source of your problem carefully inspect all of your shower heads faucet aerators and plumbing fixtures.
Resist deposition of mineral hard water buildup mineral deposition like lime inside the hot water tank and plumbing pipes.
So a lot of people crank it up as high as they can get and they ll get it up to 140.