Serval Gas Refs
Were not recalled because of owners not performing simple maintenance on them, they were recalled because many people DIED from CM poisoning when they improperly tried to convert natural gas units to run on propane and then used them in small poorly ventilated hunting cabins and fishing houses.
We have a fully restored pre-WW2 Serval N-gas ref here that cools fine, but when we test it for CM output it pegs our test meter at over 1000 PPM of CM. I would not dare to use this ref indoors.
I would like to see a copy of the simple maintenance that was supposed to be performed on these units, We have the service manual and according to it everything should be fine, it has a beautiful blue flame in the generator chamber.
Gas refs disappeared because they not only performed poorly, cost more to run than electric refs and in most cases did not last as long as electric models, When was the last time you saw one still running compared to the thousands of old electric refs you still running and cooling just fine.