The answer is probably. Filters don't last that long so you may want to change the filter for the new season anyway. The best way if your filter can be taken apart, is to use an empty filter, (ie take out the charcoal and reassemble). Clean the system, then replace with a new filter. Cleaning the system will probably clog the charcoal so it will not be doing its job in the future. Not a problem in this country as we have good clean water, but abroad is a different story as we are not used to the local bugs. Unless the van is used continuously the filter actually can cause more harm than good. The filter will remove clorine which is there to brevent bacteria. Take it out and leave standing for a few weeks in storage and what have you got, bacteria, and it just loves the dark warm conditions. So an inline filter should be sited just before the outlet, which is not the case on many vans. For some reason they are situated on the inlet. But not many of us collect our water from local rivers so the filter is removing very little, but it is removing the antibacterial properties that the water company put in.