We purchased a boilermate wh-7 41 gallon tank for our in floor heating unit in 2001. Since then we have had to replace the smart control unit three times. now we are looking at other options to replace the tank because we are concerned that replacing the smart control again will not be very smart. We have replaced them every year and a half @ $130.00 each time. This system rates far below what we were sold. We would like a tank that will run trouble free for at lest 8 years.