Mobile RV Rooftop AC Replacement - On-Site in Florida
Coast to Coast RV Repair replaces Dometic, Coleman Mach, and Advent rooftop AC units on-site at your campsite or driveway - same-week scheduling across Florida.
Coast to Coast RV Repair replaces Dometic, Coleman Mach, and Advent rooftop AC units on-site at your campsite or driveway - same-week scheduling across Florida.
Certified technicians. $299 service call. Same-week scheduling. Call (866) 437-4848.
Dometic and Coleman Mach Unit Compatibility and BTU Sizing
Coast to Coast RV Repair carries or can source the three units that cover 90% of Florida replacement calls: the Dometic Brisk II 13,500 BTU (model B13516.XXX1C0), the Dometic Brisk II 15,000 BTU (model 15B13DCxxxx), and the Coleman Mach 8 15,000 BTU (model 48203-8696). Sizing matters more than most owners realize. A 13,500 BTU unit is rated for roughly 300 square feet of living space at a 20-degree delta-T. A Class A floorplan over 35 feet in Florida July heat will run continuously and still underperform. Our technician Jesse measures the interior footprint, checks the existing electrical breaker size (typically 15A or 20A at the rooftop distribution), and confirms the roof cutout dimensions (standard 14.25 x 14.25 inches) before ordering. Advent Air 15,000 BTU units are an option for weight-sensitive applications - the Advent ACM150 comes in at 87 lbs versus Dometic's 97 lbs for the 15K model. All three manufacturers ship with a 2-year parts warranty; labor warranty on our installs is 90 days.
Roof Access, Gasket Replacement, and Leak Prevention
Every rooftop AC replacement includes a new foam or EPDM roof gasket - this is non-negotiable on our service calls because a failed gasket is the leading cause of water intrusion behind the ceiling liner. We use Heng's Industries 90085-C foam gasket kits for Dometic units and the Coleman-OEM foam pad (part 6751-4801) for Mach installs. The roof deck around the cutout is inspected for soft spots consistent with prior moisture infiltration. If we find delamination extending beyond the gasket footprint, we flag it and pause the AC install until the customer decides whether to address the roof damage first - pushing a new unit onto a soft deck shortens its life and can void the manufacturer warranty. Torque spec for Dometic Brisk II mounting bolts is 35 inch-pounds per the Dometic SLA RV AC service manual; over-tightening cracks the ABS lower shroud. On rubber (EPDM) roofs we apply a 3-inch self-leveling lap sealant bead around the gasket perimeter after installation.
Electrical Requirements and Soft-Start Integration
Rooftop AC replacement is also the right time to evaluate soft-start integration. A standard Dometic Brisk II draws 13.2A locked-rotor starting current, which trips 30-amp pedestals and generator breakers during compressor startup. Installing a Micro-Air EasyStart 364 (model ASY-364-X96-IP) or SoftStartRV unit reduces locked-rotor current to under 7A, allowing single-AC operation on a 2,000-watt generator or a 30-amp service. We wire the soft-start during the replacement without adding significant labor time since the control box is already open. The existing 10 AWG or 12 AWG supply wire is checked for heat damage at the ceiling distribution box - degraded insulation is replaced before the new unit goes online. On dual-AC Class A rigs (such as the 2017 Thor Palazzo 33.3 or Forest River Georgetown 36B7), each unit has its own dedicated 20A circuit; both are megged before commissioning.
Commissioning, Performance Verification, and Post-Install Checks
After installation, the replacement unit is run through a full performance test before our technician leaves the site. We measure supply air temperature at the closest ceiling register using a calibrated thermocouple - Dometic specs a 50 to 60 degree Fahrenheit delta-T between ambient and supply at standard conditions. Ambient above 95 F (common in South Florida from June through September) will reduce delta-T to around 40-45 degrees; that is normal and not a sign of a defective unit. We also confirm the drain pan is level within 0.5 degrees so condensate drains out the rear exit port rather than pooling inside the shroud. The thermostat wiring is verified pin-for-pin against the Dometic HPCom or Coleman Touch Pad controller wiring diagram. Owners receive a written service record with the unit model number, serial number, install date, and a reminder for the 12-month coil cleaning recommended by Dometic Service Bulletin SB-2021-004.
Also see: AC & Heating Services
This page covers rooftop ac replacement specifically. For the full range of ac & heating services we offer, visit our AC & Heating service overview.
Case Study: Compressor seized on a 2019 Dometic Brisk II 13,500 BTU unit - capacitor failed first, compressor ran unprotected and locked up within 48 hours
RV: 2019 Keystone Cougar 33MLS • Location: Larry and Penny Thompson Park, Site 47, Kendall • City: Miami
Symptom: Rooftop AC making loud rattling noise and blowing warm air after a weekend at the park
Diagnosis: Technician confirmed seized compressor via amp-draw test (locked rotor current 42A vs. rated 14.3A). Shroud inspection revealed cracked capacitor housing consistent with moisture intrusion through a deteriorated roof gasket.
- Diagnosis: Amp-draw and voltage test confirmed locked compressor; roof gasket found cracked at rear corners letting rainwater pool in the control box
- Parts staged: Replacement Dometic Brisk II 15B13DCxxxx (15,000 BTU upgrade) and Heng's Industries foam gasket kit staged the following morning
- Roof prep: Old unit lifted with two-man team, old gasket scraped, roof deck cleaned and inspected for delamination - none found
- Installation: New unit set, torqued to 35 in-lb per Dometic service manual, control wiring re-terminated, drain pan verified level
- Commissioning: Unit ran through full heat-load cycle; supply duct temps measured at 53 F delta-T, within Dometic spec of 50-60 F
Outcome: Full cooling restored same visit. Owner upgraded from 13,500 to 15,000 BTU at the same labor cost, now covers the rear bunkhouse on hot Miami nights.
Time on-site: 3.5 hours • Total cost: $1,420 installed (unit + Heng's gasket + labor) • Dealer alternative: $1,900+ at a Miami-area dealer with a 3-week wait
“They showed up the next morning and had cold air blowing before lunch. The upgrade to the bigger unit was a great call - Site 47 in July is no joke. - Cougar owner, Larry and Penny Thompson Park, Kendall”
Rooftop AC Unit Comparison - Common Florida RV Replacements
| Model | BTU | Weight (lbs) | Starting Amps (LRA) | 2-Yr Parts Warranty | Installed Price Range |
|---|---|---|---|---|---|
| Dometic Brisk II 13.5K (B13516.XXX1C0) | 13,500 | 78 | 14.3A | Yes | $1,150 - $1,400 |
| Dometic Brisk II 15K (15B13DCxxxx) | 15,000 | 97 | 17.1A | Yes | $1,300 - $1,600 |
| Coleman Mach 8 15K (48203-8696) | 15,000 | 91 | 16.8A | Yes | $1,250 - $1,550 |
| Coleman Mach 15 (48204C-8696) | 15,000 | 104 | 18.2A | Yes | $1,350 - $1,650 |
| Advent Air ACM150 | 15,000 | 87 | 15.9A | 2 years | $1,350 - $1,700 |
| Dometic Blizzard NXT 15K (B59516.XXX1C0) | 15,000 | 99 | 16.4A | Yes | $1,450 - $1,950 |
Signs You Need Rooftop AC Replacement
- ✓AC unit runs continuously but cannot get the interior below 80 F even on a 90-degree day
- ✓Loud rattling, banging, or grinding noise from the rooftop shroud during operation
- ✓Unit is 10 or more years old and has needed two or more repairs in the past two seasons
- ✓Compressor hums but does not start, or trips the breaker at startup
- ✓Water dripping from the ceiling vent inside the RV when the AC runs
- ✓Visible cracks in the rooftop shroud or pan, or the lower air distribution box is cracked and leaking conditioned air into the ceiling space
Rooftop AC Replacement - Pricing
Typical price range: $1,150 - $1,950
All calls start with a $299 service-call fee that covers the technician's trip to your location and the first hour of diagnosis. That $299 applies toward any repair you authorize - it is not an additional charge on top of the repair. Pricing shown is a national average range; your exact quote is provided in writing on-site before any work begins.
Rooftop AC Replacement - Typical Florida Cost Breakdown
Rooftop AC Replacement - Common Questions
Straight answers from our rooftop ac replacement service call log.
How long does a rooftop AC replacement take on-site?
Most single-unit swaps take 2.5 to 4 hours on-site. A dual-AC Class A replacement where both units are being swapped the same day runs 5 to 7 hours. We carry all standard gaskets and control board connectors on the truck, so we rarely have to make a parts run mid-job.
Can you replace a 13,500 BTU unit with a 15,000 BTU unit?
Yes, in most cases. The roof cutout is the same 14.25 x 14.25-inch opening on both Dometic and Coleman units. The only constraint is the ceiling distribution box - some older rigs have a smaller plenum that limits airflow. We check that before committing to the upgrade. The 15K unit also draws about 3A more at startup, so we confirm the circuit is protected by a 20A breaker, not a 15A.
Does my RV manufacturer warranty cover AC replacement?
Factory warranty on the RV typically covers the air conditioner unit for 1 year. The AC manufacturer (Dometic, Coleman) provides a separate 2-year parts warranty on the unit itself. If your rig is still under the factory warranty, call your dealer to authorize an out-of-network service call - most will authorize Coast to Coast RV Repair, and we have the technician credentials to document the repair for warranty records.
What is the life expectancy of a new rooftop AC on a Florida RV?
In a Florida year-round-use environment, expect 8 to 12 years with annual coil cleaning and gasket inspection. UV exposure degrades the ABS shroud faster than in northern climates - plan on a shroud replacement around year 6 to prevent cracking that lets water into the motor housing.
Should I install a soft-start kit when replacing the AC?
We recommend it for any owner who wants to run on shore power under 30 amps or on a generator under 3,000 watts. The Micro-Air EasyStart 364 is the most reliable unit we have installed - it takes about 60 extra minutes to wire in during the replacement and costs $299 to $349 installed. Worth every dollar if you boondock or stay at parks with weak pedestals.
Do you haul away the old AC unit?
Yes. We remove and dispose of the old unit at no extra charge. If the unit is less than 5 years old and the compressor is the only failure, we can sometimes sell it for core credit - ask our technician when they arrive.
More AC & Heating Services
Other specialized repairs under ac & heating - all done at your location, no tow required.
Where We Provide Rooftop AC Replacement in Florida
Coast to Coast RV Repair runs rooftop ac replacement jobs across these cities. Click your closest one for local-specific info, response times, and campground coverage.