I bought my home in Vancouver WA in 2001 and it has an Apollo heating system. When I moved in I replaced the Apollo hot water heater with a Bradford White. After about ten years the Bradford White started leaking and I replaced it again. I have two heat exchange units. One on the first floor under the stairs and the second in the 2nd floor attic. The blower motor failed in 2015 on the s1st floor unit and I had the motor replaced. This week that capacitor failed on the 1st floor unit and I replaced it. The heating system has always heated my home well and the cost in my natural gas bill is reasonable to me. To date I have had no problems with leaks. All the homes in my neighborhood are the same and some have had problems. Next door the second floor unit sprang a small leak spraying water in the attic that was not noticed until the walls started turning green. It was a costly repair for my neighbor. I do not see a need to retrofit at this time for my home. I would like to install some water leak ropes that will notify me of any leaks. Also, I would like to get my hands on a spare blower motor fan assembly just in case I need one in the winter. Personally I think the Apollo heating system has been great for my home and family.