Keeping a roof air conditioner healthy comes down to three things: the return air filters, the coils and drain openings, and the shroud and roof gasket. Anything deeper inside the unit is service work in most makers' manuals.
RV Air Conditioner Maintenance: Filters, Coils, Drains and the Yearly Checks
At a glance
- Filters: wash every two weeks of use on Dometic and Coleman-Mach units, every four weeks on a Furrion.
- Once a season: check the mounting bolts and the shroud, and have the fins and blower wheel cleaned.
- Coil cleaning is disputed: Coleman-Mach reserves it for a trained technician, while Winnebago tells owners to clear the coils.
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What maintenance does an RV air conditioner need?
The rooftop air conditioner needs one short routine at the start or end of each season, plus filter cleaning while you use it. Dometic's air conditioner warranty statement sets the yearly part (bolts, fins and blower wheel) at the owner's cost, about an hour's work.
- Wash the return air filters and let them dry fully before refitting.
- Wipe the ceiling assembly and control panel with a damp cloth and, if needed, mild detergent.
- From the roof, look over the shroud for cracks or impact damage and check that its four screws are snug.
- Check the mounting bolts for correct tightness. Do not keep cranking them.
- Have the condenser and evaporator fins inspected, cleaned and combed, and the blower wheel and condenser fan cleaned.
- Clear leaves and dirt from the rooftop unit's ventilation grilles, and clear the condensation drain openings.
- Rinse rust colored stains from the roof around the unit with an RV roof-safe detergent.
Intervals, torque and the owner/technician line differ by maker, so work from your own model's manual. Blower motors need no oiling, per both Dometic and Coleman-Mach.
How often do I clean the filter?
Every two to four weeks of use, depending on the maker; it is the one job every maker leaves to you. Coleman-Mach warns that a clogged filter cuts air volume and can ice up the evaporator coil, and it is the first check on the troubleshooting page.
| Maker | Cleaning interval | Method |
|---|---|---|
| Dometic | Minimum every 2 weeks of operation | Wash with soap and warm water, dry fully |
| Coleman-Mach | At least every 2 weeks in operation | Clean or replace the two filters |
| Furrion | Every 4 weeks of use, or more | Warm soapy water; replace at least every 12 months |
From the Dometic rooftop AC manual, the Coleman-Mach 45000 and 38200 series manuals and the Furrion Chill manual. On a Coleman-Mach ceiling assembly, pull the tabs to drop the two grilles and lift out both filters (a flush mount needs its four grille screws out first). Penguin II filters slide out of the end of the box and go back domed side of the handle up. Never run the unit with a filter missing: Coleman-Mach says lint and grease then collect in the coil.
Tip: A denser aftermarket filter is not a free upgrade. Airxcel's warranty will not support HEPA filters or other material it has not recommended for Coleman-Mach units. Ducted and non-ducted ceiling assemblies take different filters (9430-3441 and 8430-3801).
On a Dometic CCC 2 thermostat, a filter icon appears after 1000 hours of fan run time; after refitting the clean filter, clear it by holding INSIDE TEMP and the °F/°C button for three seconds.
How do I clean the coils?
It depends whose unit is on your roof: makers disagree on whether this is owner or technician work, and none prints an owner method with a brush, fin comb or named cleaner.
- Coleman-Mach (38200 Series): maintenance, cleaning and service of the rooftop unit only by technicians qualified in flammable refrigerants.
- Dometic: the warranty statement lists cleaning and combing the fins as yearly owner-cost maintenance, while the 2025 manual leaves service and maintenance to a qualified service person.
- Winnebago: its 2026 towables manual tells owners to clear the evaporator and condenser coils, filter and pan.
- Furrion: no coil step for owners.
Dometic mentions a cleaner only in the manual for its soft start accessory: an appropriate coil cleaning product when air flow over the condenser is insufficient. If you are not qualified to work on the rooftop unit, have an RV technician clean the fins and blower.
Tip: Skipping it is not covered either way. Dometic's and Airxcel's warranties both exclude damage from failing to do the routine maintenance.
Drain openings and roof stains
Clear drain openings let condensation run off the roof. Only Furrion gives owners a drain step; Winnebago's coil instruction covers the pan. Furrion adds that condensation dripping from the base pan leaves rust colored stains on the roof, and that periodic cleaning with an RV roof-safe detergent removes most of them.
The shroud and the roof gasket
Check both each season; the mounting bolts are what keep the roof sealed. Coleman-Mach asks for a periodic look at the shroud: four mounting screws and washers snug, no cracks, no impact damage. Dometic warns against forcing a shroud off, because broken screw holes mean a new shroud.
Mounting bolts are checked from inside the RV, and the figure differs by maker.
| Maker | Bolt tightness | What it does |
|---|---|---|
| Dometic, models other than FreshJet 3 | 40 to 50 in·lb, all four evenly | On the Penguin II, compresses the roof gasket to about 1/2 inch |
| Dometic FreshJet 3 | 22.2 in·lb, all four evenly | Foam torque tabs touch the roof |
| Furrion Chill | 40 to 50 in·lb, all four evenly | Compresses the roof gasket to about 1/2 inch |
| Coleman-Mach 38200 | No figure given | Gasket indicating tab pulled down even with the roof |
Gasket tab method from the Coleman-Mach 38200 Series instructions.
Tip: Too loose and the roof does not seal; too tight and you crush the gasket or damage the base pan and ceiling template. Jayco tells owners to inspect the bolts for tightness to prevent leakage, not to over-tighten, and to expect the gasket to need replacement eventually.
Where to stop
Lifting the shroud exposes 120 V wiring and capacitors that hold a charge after the power is off. Switch off the breaker and unplug shore power before any work on the unit, and treat anything behind that panel as a job for an RV technician. Dometic tells installers to wait a full five minutes after cutting power and confirm with a multimeter that the capacitor is discharged. Mind the roof edge too.
Common questions
How often should you clean the coils on an RV air conditioner?
Once a season is enough, ideally before the hot months rather than after them. Book it with an RV service center or a mobile RV technician on the same visit as any other roof work, so the shroud only comes off once.
How do I clear a clogged RV AC drain?
With the breaker off, clean the condensation drainage openings on the rooftop unit from the roof. If water still gets in after that, Furrion points to damaged seals and sends you to an authorized service agent.
Can I wash an RV air conditioner filter, or do I replace it?
Both. Washing is the routine, and a worn or torn filter gets replaced; Coleman-Mach recommends carrying spare filters in the RV.
Should I cover my RV air conditioner in winter?
The RV builders say yes; the AC makers are silent on it. Jayco's storage checklist says to cover the roof air conditioner if equipped, and Winnebago's maintenance table says to cover the unit outside when it is not in use.