A friend of mine who has had his DeFever 55 for over 20 yrs had a different problem with the onboard Halon system. The dual tank system was installed when he purchased the boat. An electrical short started a fire in the ER. The stbd tank reacted properly but the distribution system had perished with age and so was not effective against the fire. The second (portside) tank did not open but unfortunately was directly mounted above the fire. The heat exploded the tank. It created a two ft. diameter hole in salon floor and completely destroyed the galley area. He managed to put out the fire with his saltwater deck wash. Walters repairs to the ER and everthing else is an amazing story for another time - especially for a 76 yr. old singlehander.
He has NOT reinstalled any automatic fire suspression system that involves hi-pressure tankage.