RV Air Conditioner Maintenance Part 1: The Inside Job

As summer draws closer (or for those of us in the southwest, as it continues on unabated), air conditioning becomes more of a critical issue. Here begins a two-part piece on the hands-on of air conditioner maintenance. We’ll address the most common of RV air conditioning systems--the roof mounted ac unit. Exposed as it is to the elements and low-hanging branches, the roof mounted unit is prey to a lot of problems. But let’s start "inside" first.

The easiest part of the assignment is simply cleaning or replacing air filters. Check your owner’s manual to find instructions for getting the filter out of the unit--typically by removing a couple of screws and pulling a grill loose to access the filter. This filter, although cleaned in the last few weeks, is in serious need of cleaning again.


Some ac unit filters can simply be washed in warm, soapy dishwater, thoroughly dried, and reinstalled. In use, washable filters should be removed and cleaned a couple of times a month if used in dusty areas; once a season should be enough elsewhere.

Some ac filters are not washable but must be replaced. Here’s a thought: You can replace nearly any ac filter with an after-market "electrostatic" filter that is said to capture more dust and pollen than typical OEM filters. We’ve never actually tested them out, but if you’ve got twenty bucks to check the theory out, visit a Camping World store for these super filters.

While you’re working with the filter, check out your unit’s ducting. Some rigs have simple metal channels to deliver chilled air; others may use heat distribution hoses. If you can, it’s a good time to vacuum out your ducts while servicing the filter.

So much for filters, if you’re feeling a bit more adventurous, check out unit security. We’re not talking about somebody stealing your ac unit, but rather having the thing get loose and fall of your rig. An ac unit is bolted onto your rig roof top, and generally speaking, the mounting bolts come down through the roof and snug up inside the rig. Often these can be accessed by removing the inside trim that surrounds the unit. Be sure to disconnect the power before puling this trim--you may expose electrical fittings you don’t want to get your fingers into. Once you spot the mounting hardware, make sure it’s tight. Incidentally, water leaking into your RV through the ac unit can sometimes be traced to loose mounting bolts.

We'll get onto the outside work in our next installment.