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Grumman Sunstream Solar System-Life Expectancy?

JB_6 Member Posts: 10
Hello-I'm wondering about a Grumman Sunstream Solar system, specifically what the expected life cycle is of this system. I'm also wondering about the piping schematic best suited for this system. Am I correct in understanding that the solar panels are constructed with aluminum instead of copper tubing? Is that a negative aspect of this system, or a positive one in your opinion?

I have absolutely no experience with these systems and haven't found much information on the internet yet. As good as it once was, should I attempt to revive this 30-35 year old system, or would my customer be better served with a newer technology system instead? Primary Secondary Pumpimg?

Any thoughts, suggestions,and  comments are greatly appreciated in advance.


James B. ( Jim ) McCarroll

JB Plumbing & Solar


  • Kevin_in_Denver_2
    Kevin_in_Denver_2 Member Posts: 588

    The first thing to do is check the pH of the collector fluid. If it's over 7, it may well have some life left in it.

    If it's slightly acidic, but not leaking, you can mitigate the pH somehow, I've only done it with a hot tub. (baking soda?)

    If the system runs now, I'd try to keep it going, but once one of the collectors starts leaking, replace them all. The balance of the system can be repaired as items fail. The expansion tank usually dies in 20 years.

    If the system has just been sitting in the sun for years, I wouldn't expect the aluminum absorbers to be in good shape. Fatigue from thermal expansion has probably caused a crack somewhere.
    Superinsulated Passive solar house, Buderus in floor backup heat by Mark Eatherton, 3KW grid-tied PV system, various solar thermal experiments
  • joseph annon
    joseph annon Member Posts: 43
    Life of Grumman Sunstrams

    I have found that the Grumman collectors used in my area are all copper and the collectors have proven to be very durable and if there are leaks they are usually repairable.Just be careful when removing the glass. Getting a couple of inexpensive suction cups makes this really easy. Maybe ten percent of the collectors I have found are not worth repairing and most of those are because of the cost of repalcewing broken glazing. The two biggest challenges I have found is in getting replacement water side pumps. UP15-18SUs  And making sure the HX is clear of mineral buildup. once those HXs are completely plugged they are very difficult to clear. If the tank has failed I will use a tank with a heat exchanger and use the collector pump and control from the Grumman unit. 
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