Never run out of hot water again with this thermal water heating system from Alternate Energy Technology. The water is heated in the drainback reservoir while passing through simultaneously with the heating water. The system is designed with a closed loop that prevents the heating water and the stored water from mixing. The system is egineered witha a draiback reservoir allowing the unit to be used in colder climates. The tank holds 80 gallons and is paired with a 52 square foot solar collector.