What we see most
The half of the unit nobody looks at
Everyone thinks of a rooftop air conditioner as the thing on the roof. Mechanically it is two assemblies: the unit itself up top, and the ceiling assembly — the air distribution box — that carries the return filter, the control wiring, the thermistor and, on many coaches, the control board.
That matters because plenty of "dead A/C" calls are resolved from inside the coach at eye level. Getting on the roof of someone's rig is not free — it takes time, and it has its own risks in this heat. We start where the evidence points.
Ducted or non-ducted changes the whole diagnosis
Dometic units are installed both ways. On a non-ducted coach the air comes straight out of the ceiling assembly, so weak airflow points at the unit or the filter. On a ducted coach the air is distributed through the ceiling to multiple vents, and one weak vent is usually a duct problem — a crushed run, a disconnected boot, or a divider that has shifted.
Chasing a ducted airflow complaint as if it were a compressor fault is a good way to spend money on the wrong thing. We establish which system you have before quoting anything.
Dust is a maintenance item here, not an afterthought
A rooftop unit cools by rejecting heat through its condenser coil. In the desert that coil packs with fine dust, and a unit that cannot shed heat behaves exactly like a unit with a failing compressor — it runs constantly, it cools less and less as the day heats up, and eventually it trips.
Coil cleaning and filter service on a schedule is the cheapest thing you can do for an RV air conditioner in this valley. It is also the first thing we check when someone says the unit "got weaker this summer."
What we do
Capacitor and start-component diagnosis, fan and blower motor replacement, control board and thermostat faults, thermistor and sensor testing, ceiling assembly and air distribution box service, ducted airflow diagnosis, condenser and evaporator coil cleaning, drain pan and gasket leaks, and full unit replacement when the numbers say replace.
Pricing
Common questions
Do you have to get on the roof?
Not always. A real share of no-cooling faults are in the ceiling assembly, the thermostat or the wiring between them, all reachable from inside. We go up when the diagnosis sends us up.
I have two roof units. Can you do both in one visit?
Yes — one trip, both units. They're independent systems, so it's entirely normal for one to fail while the other is fine.
Are Dometic parts still available for an older unit?
Usually, yes. Capacitors, fan motors, boards and ceiling-assembly parts are well supported across the common Dometic families, and we carry the frequent failure items. We'll tell you before we order if yours is an exception.
Would a soft start help?
It helps with starting — running the unit on a generator or a limited pedestal. It does not make a healthy unit colder, and it won't rescue one that's failing. More on RV air conditioning →
Related
Stuck right now?
Call or text — fastest way to reach us. In summer, no-A/C calls go first.