It’s a lot worse than I originally thought. A solenoid malfunction was not the problem just a warning symptom. It appears that the silicon seals in secondary heat exchanger have deteriorated and is leaking water. The water is one of the by-products of propane combustion. The leak can be dangerous because toxic carbon monoxide gas, another by-product of combustion, might also leak out. To keep that from happening the furnace has a safety device that will not let it turn on.
The heat exchanger must be completely replaced. It is under a limited lifetime warranty which means the part is free but the labor is not. And the part must be ordered so for the next six days I will be without heat except for the wood stove. Tonight the low will be 26 degrees but the weather will be a little warmer starting on Sunday.