I'm sure my list will grow, but I'm keeping duplicates of many RV parts in the RV:
- Dometic toilet valve (tip: Don't buy the non-Dometic knock-offs, I bought 2 and they both leaked)
- Hot water heater anode rod
- Hot water heater electric heating element
- Hot water heater electric on/off switch (replaced this already)
- Water pump and connection hoses
- Sewer hose, water hoses, water pressure adapters, etc
I also have backups of certain appliances in case the primary appliance fails:
- Big Buddy propane heater in case the RV furnace fails
- Electric oil-filled radiator heater in case the Big Buddy fails or I'm out of propane. Plus I'd rather use the CS electricity instead of my propane
- Electric fans in case the RV air-conditioner fails
- Induction cooktop in case the RV propane stove fails. Plus I'd rather use the CS electricity instead of my propane
- Portable 100W solar panels and charger so I can charge my RV house battery in case the RV converter fails
- ...and (drumroll...) 5-gallon bucket in case the RV toilet fails
I plan to get a 2nd air-conditioner (the bedroom is pre-wired for 2nd A/C) not because I need it, but in case the main RV air-conditioner fails. I'm actually considering a portable air-conditioner instead that vents out a window, just so I can wheel it around to use where it's needed.
Also plan to get a dual-fuel (gasoline/propane) inverter generator. Looking at the Champion 3500W Dual Fuel.
Love the RV. But I don't trust it 100%, so I've learned to have spare parts and backup systems, and keep my tools with me.