As an added bit of help:
If you open the access panel that is between the fridge and the closet, you can easily see the heater. On the bottom there is an easy to turn valve. Do NOT leave the valve all the way open. Turn it all the way off, then all the the way on, and decide about where the middle setting would be. Set it at the middle-ish.
This took us from pure hate for the system to never thinking of it again.
By using the hot water shower valve solely and having adjusted the heater flow valve, we have no complaints with our now 'continuous' hot water.
The valve on the heater flow is the answer. Water going too fast through the heater caused surges in temperature that made it impossible to regulate final output/pleasant temperature.
__________________
|