This picture shows a few of the more important parts to have on hand. They are all available for delivery at any time, but to run for two days with busted door shocks is really not necessary if you have a set in stock. You will need them eventually. The other parts are also good to have in stock but they usually give some warning that they are going out. For example if you pilot will not stay lit you check if you have a good flame if so it's the thermocouple if the flame is very small its the pilot orifice both cheep $15 dollar parts with $35 next day shipping cost so it's cheaper the have them in stock.