a. Lack of service.
b. Loss or low level of antifreeze liquid in the closed circuit of the solar water heater system.
c. Partial or total shading of the absorbent collector area.
d. Little sun duration.
e. Leakage in the plumbing or fittings of the closed circuit system.
f. Malfunction antifreeze-air entrapment in the closed circuit.
i. Damage to the safety valve.
g. Wrong orientation, installation or wiring.
