An improperly sized gas line as mentioned above.
Tankless water heater water goes cold.
Another problem that tankless water heaters can run into is that of a cold water sandwich a plumbing term given to sudden temperature fluctuations when your tankless water heater produces hot and cold water intermittently.
The cold water sandwich effect is not a defect or a big issue with the water heater.
This might seem painfully obvious especially if you live in a colder climate but you d be surprised to know how many people don t even consider the fact that the outside temperature is affecting the water temperature in their tankless heater.
Rinnai heater puts out water which fluctuates temperatures from very hot to very cold but will not hold a moderate temperature throughout shower.
So by knowing this we can avoid going to bath immediately after one person finishes his turn.
My tank less water heater goes.
To fix this do not touch anything and let the intruding.
If you live in a cold climate like massachusetts and are looking for a tankless water heater go gas.
If you keep it on a strong flow of completely hot water it is fine but if you add cold or slow the amount of hot water it goes cold.
One of the likely possibilities for a cold tankless heater is the cold external temperatures.
Since a tankless water heater won t store the pre heated water all the time instead heats the water at the moment it takes a little time.
Water fixture the problem could be with the temperature regulating valves you.
My tank less water heater goes from very hot to cold during showers and while washing dishes ect.
Before it fully warms up and starts heating the water you get a short run of cold water.
When you turn out other faucets at the same time that increases water flow out of the water heater and keeps the heater turned on.
A tankless is a direct fired appliance and the water is actually heated to a much higher temp than the touch pad control indicates.
Either take the shower head off and soak it in vinegar water for 1 2 hour to clean it or tap out the water restrictor screen in the center of it and see if that solves the problem.
Volume of cold water go down the drain.
So when the ground water gets colder in winter the electric tankless water heater may not give you the endless hot water you re expecting.
Why the tankless water heater s size matters.
Turns cold when house demand is low.
This can be caused by.
This problem happens because the heat exchanger the part that actually heats the water takes a while to warm up.
A water flow servo on the unit them meters the appropriate cold water after it leaves the burner area to arrive at the set point temp plus or minus 2 f.