A car has one clock that matters: the odometer. A motorhome has three, and they rarely agree. Miles say the chassis oil is fine. The calendar says the roof sealant is overdue. The season says the water lines need antifreeze before the first hard frost.
Miles cover the vehicle
Engine oil, filters, brakes and tyres on the chassis follow the same mileage logic as any van. The manual for the base vehicle sets those intervals, and they are usually the easiest to keep on top of.
The calendar covers the living side
Roof and window seals, gas system checks, smoke alarm batteries and the leisure battery all age whether or not the thing moves. A motorhome that sat on the drive all summer still needs its sealant checked, and water ingress is the most expensive problem a van can have.
The season covers everything with water in it
Before a frost, fresh water tanks, pipes and the boiler need draining or winterising. In spring they need sanitising and refilling. Miss the autumn job once and a split pipe or a cracked water heater is the usual result.
One due list
The hard part is not doing any of these jobs. It is remembering which of the three clocks is about to run out. Copy the intervals from the chassis manual, the habitation manual and the appliance manuals once, and a single list of what is due next does the rest.
RVKeep is a phone app that counts all three clocks against the intervals from your own manuals and puts everything into one due list for the rig.