Bill Christian

I installed Grumman solar systems in the 80's. They were great and could last 50 years (replacing tanks every 25 or so because that's how long ANY hot water tank lasts), and doing the very minor things you'd do to any heating system. If you do remove it, and if the panels are 4 x 10, email me because I'd be interested in them. Thanks!

Grumman made extremely good equipment. I would be amazed if it was not an easy fix. I'd expect it to last forever. Tank will need replacement, every 15-30 years, unless you splurge on stainless steel or are good about replacing the sacrificial anode rod (NOBODY replaces that when they should... preferring to sacrifice the tank instead. I could step you through troubleshooting.

I installed Grumman Sunstream systems in the 1980's. Some of my installs are still running fine. "There is nothing to break that can't be fixed". I believe the system can be easily repaired by a good solar technician. There are no leaks in the antifreeze loop - gauge reads 30 psi. Most likely you need a new 10k ohm sensor ($ or fix a loose connection.
But you need a new tank. You DO NOT NEED a very expensive solar tank with built-in coil. A standard electric water heater with a simple modification will do. (The antifreeze-to-water heat exchanger is in that white plastic case, not the tanks.) Email me for help, at bill_christian    at     comcast.net.