is my titan scr3 malfunctioning?

[zardoz50]

I have a titan scr3 tankless water heater which I assume is supposed to supply hot water on demand. If that is the case, is the pipe leading away from the device (supplying the house) as well as the hot water pipe under my kitchen floor supposed to be hot all the time, 24/7?

 

[MicEd69]

No. The tankless water heater starts heating water when water flows through it. It cannot heat water in a pipe that is simply connected to it.