Electrical and Systems
RV Rooftop Air Conditioner Service, Repair and Replacement
Typical range
$750 to $4,500
Shop hours
2 to 14
Labor rate
$260/hr
The short answer
Rooftop air conditioner work covers weak cooling, capacitor and compressor failures, control board and thermostat faults, and full unit replacement on Coleman, Dometic, and Furrion equipment. Work runs $750 to $4,500, or 2 to 14 hours at $260 per hour plus equipment.
01
What this work actually involves
Rooftop air conditioners are sealed systems with no service ports, so the repair question is almost always about the electrical side and the airflow, not about refrigerant. The most common single failure is the start capacitor. When it weakens, the compressor tries to start, draws locked rotor current, and trips out on thermal overload, which the owner experiences as a unit that hums and then quits. A capacitor is inexpensive. Running a coach on a weak one until the compressor windings burn is not.
Southern California low desert conditions are what actually kill these units. A rooftop air conditioner rejects heat to ambient, and when ambient in Palm Springs, Indio, Palm Desert, or Coachella is 118 degrees, the head pressure climbs to where the compressor has almost no capacity left. Add a dirty condenser coil packed with dust from a storage lot and a shore pedestal delivering 104 volts, and the unit runs continuously, cools nothing, and eventually fails. Half of the low desert replacements we do were preventable with a coil cleaning and a hard start kit.
The other frequent problem is distribution rather than the unit. Ducted coaches lose enormous capacity to separated duct runs above the ceiling, gaskets that have compressed and now leak return air straight back into the supply, and a return filter nobody has ever cleaned. We check the roof gasket seal and the duct path on every weak cooling complaint before pricing a new unit, because a coach that cools poorly on both units almost never has two failed compressors.
Systems and brands we work on: Coleman, Dometic, Furrion, Truma.
Location: All work is performed at our Yorba Linda facility. We do not offer mobile, roadside, or fleet route service.
02
What the job includes
- Start and run capacitor testing and replacement
- Compressor amp draw, locked rotor, and winding resistance testing
- Condenser and evaporator coil cleaning and fin straightening
- Fan motor, blower wheel, and bearing replacement
- Control board, thermostat, and multi-zone control diagnosis
- Hard start kit and soft start module installation
- Roof gasket replacement and mounting bolt torque correction
- Ducted system inspection, duct reconnection, and return path repair
- Full rooftop unit replacement including ducted and non-ducted conversions
- Supply voltage verification at the unit under running load
03
When you need this service
- Unit hums and then trips out without the compressor starting
- Air blows but never gets cold, or cools only in the morning
- Water dripping into the coach from the ceiling assembly
- Loud rattle, grinding, or vibration from the rooftop unit
- Breaker trips whenever the compressor tries to start
- One ducted register cold and the rest of the coach barely moving air
- Unit runs continuously in low desert heat without holding temperature
04
How we do it, step by step
- 01
Electrical measurement first
Supply voltage at the unit under running load, compressor amp draw, and capacitor value all measured before anything is opened up. Most failures declare themselves here.
- 02
Airflow and coil inspection
Condenser and evaporator coils inspected and cleaned. A coil packed with storage lot dust destroys capacity in desert heat and gets blamed on the compressor constantly.
- 03
Gasket and distribution check
Roof gasket compression, mounting torque, duct runs, and return path checked. Return air leaking back into the supply is a very common cause of weak cooling on ducted coaches.
- 04
Repair versus replace pricing
On a failed compressor we price a replacement unit against the repair, because these are sealed systems and a compressor failure usually means the unit rather than the part.
- 05
Installation
New unit set on a fresh gasket with correct bolt torque, ducted or non-ducted plenum fitted properly, and the thermostat configured for the zone layout.
- 06
Performance verification
Supply and return temperature split measured at the register and amp draw verified after a sustained run, rather than declaring it fixed because cold air came out.
05
Pricing and posted rates
| Item | Rate or range | Notes |
|---|---|---|
| Typical job range | $750 to $4,500 | Varies with extent of damage and parts availability |
| Shop hours | 2 to 14 | Quoted after teardown, not before |
| Mechanical and electrical labor | $260 per hour | 2026 posted rate |
| Parts | 100% markup under $100, 35% over | Special order parts require a non refundable deposit at order |
| Deposit | 50% at authorization over $2,000 | Additional 25% when parts arrive on jobs over $10,000 |
| Sales tax | 7.75% on parts and materials | Labor is not taxed |
Insurance billed jobs may be billed at carrier negotiated labor rates that differ from the posted retail rates above. See all posted rates.
07
Vehicles we do this work on
Vehicle
Class A Gas Motorhomes
A Class A gas motorhome is a flat-front coach built on a Ford F53 or Workhorse front-engine chassis, typically 28 to 38 feet. Rear
Vehicle
Class A Diesel Pusher Motorhomes
A diesel pusher carries a rear-mounted diesel on a raised-rail air ride chassis, usually 34 to 45 feet with full-body paint and pa
Vehicle
Class C Motorhomes
A Class C is a coach body built onto a cutaway van chassis with a sleeping or storage cabover extending above the factory cab. Tha
Vehicle
Standard Fifth Wheels
A fifth wheel couples to a hitch in the truck bed through a kingpin and pin box, with a raised forward bedroom over the truck. The
Vehicle
Travel Trailers
A travel trailer tows from a ball hitch behind the tow vehicle rear axle on an A-frame tongue, which makes it the most sway-prone
Vehicle
Toy Hauler Fifth Wheels
A toy hauler fifth wheel carries a cargo garage behind the axles with a full-height rear ramp door. Load behind the axle centerlin
Vehicle
Park Model RVs
A park model is a towable unit up to roughly 400 square feet built with residential windows, roofing, and finishes, designed to si
08
Questions about air conditioner replacement and service
Frequently asked questions
How much does an RV air conditioner replacement cost?
Work runs $750 to $4,500, or 2 to 14 hours at $260 per hour plus equipment. A capacitor replacement and coil cleaning is at the low end. A full rooftop unit replacement with a new gasket, ducted plenum, thermostat, and a soft start module is at the high end. Two unit coaches naturally run higher.
My air conditioner hums but will not start. What is it?
That is the classic weak start capacitor symptom. The compressor tries to start, cannot break away, draws locked rotor current, and trips its thermal overload. It is an inexpensive part and a quick test. What matters is not running it that way for weeks, because repeated locked rotor starts are what burn the windings.
Why does my air conditioner barely cool in Palm Springs?
Because a rooftop unit rejects heat to ambient, and at 115 to 120 degrees there is very little capacity left in the system by design. Add a dust packed condenser coil and a campground pedestal delivering low voltage and it will run all day without holding temperature. Coil cleaning and a soft start module are the practical fixes.
Do I need a soft start module?
You need one if you want to start the unit on an inverter or on a small generator, and it is worth having regardless in low desert conditions where voltage sags. It reduces the startup surge substantially, which is easier on the compressor, on the pedestal, and on your generator. We install them routinely.
Water is dripping into the coach from the ceiling unit. Is that a leak in the roof?
Usually it is the roof gasket under the unit, or a blocked condensate drain path in the plenum. The gasket compresses over years and the mounting bolts lose torque, and then rain or condensate finds its way in around the opening. We check gasket condition and bolt torque before assuming the roof membrane itself has failed.
09
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Ready to move on air conditioner replacement and service? Bring it to Yorba Linda.