ANSWER TO QUESTION NUMBER 9
We at SEISCO discovered a long time ago that it was critically important to increase the amount of water in the tankless water heater as you increased the power.
This way we made sure that even with high power elements, much safer temperature control was accomplished. Most tankless water heaters today started at lower power ratings.
They have increased the power but not the water capacity (buffer) in the heater. This increases the high temperature conditions that occur when the heater is turned off. The latent heat, still in the elements, is added to the extremely small quantity of water the was already hot.
