Removal of the vacuum tube is intended to facilitate the operation.
It is safe to install auxiliary electric heater only behind the original solar water heater tank which has reserved electric heater installation holes.
If there are no installation holes initially reserved, the addition of auxiliary electric heaters as a temporary measure will later need to occupy the sewage outlet, the tube installation hole manifold or hole for other purposes, and it is unsafe and easy to use after modification. Abnormalities such as water leakage occur.
When installing the electric heating rod, it must be sealed to prevent water leakage.