My kerosene heater is 15 years old. I have used it maybe 5 times, for an
average of 4 days each, over those years.
I have never drained it, and it works fine. I have also used 8 year old
kerosene, and it burned perfectly well. So, unless someone can document the
deterioration that occurs in 6 month old kerosene, I will have to think it
is doesn't happen. Gasoline gums up and the high volatiles evaporate; that
can't happen to kerosene.
On the other hand, I have refueled while it was burning; and I have to
concede that is pretty stupid.
we got a retired guy who works on kero heaters in the fall and
winter. there are many people who bring the same heater back every fall
cause it wont burn right. they usually have kero in them from last
season, he cleans em out and puts in a new wick to makem burn good.i
dont know why that is that they need service every year.. lucas