smoking trains is one of the aspects i love about toy trains.fortunately the smoke doesn't bother my wife.
i always leave my smoke units on and never turn them off.i've had only two resistor's go out on me the last five year's i've been into O gauge.i have about 25 smoker's total so im having pretty good luck so far.
although i cant repair them myself no more i send them out to a pro for repair if need be.
thop........