Originally Posted By: tanstaafl.
Originally Posted By: larry818
you have to schedule around it. The water won't be warm until the afternoon and cools off as soon as the sun is off it.
Is the tank not insulated then?

My first thought was that the tank couldn't be insulated. If it was, the sun wouldn't be able to heat it up to 80. That was the only concern I would have had with the system. If you have it feeding into a propane heater, I can't see any drawback (as long as you don't mind it being on your roof I guess).