Rheem AC Not Cooling? Common Causes & How to Fix It

First, the fast checks

If your Rheem (or Ruud) AC is running but not cooling, run the five checks that fix most no-cool calls:

1. Thermostat - set to COOL, target below room temp, fresh batteries.
2. Air filter - a clogged filter chokes airflow and freezes the coil. Replace it if it's dirty (how to).
3. Breakers - reset the indoor and outdoor breakers once; repeated trips mean call a pro.
4. Outdoor unit - confirm the fan is spinning, clear debris, check the disconnect.
5. Frozen coil - ice on the lines means shut the AC off (fan ON) to thaw, then run with a clean filter.

Still warm? Here's what's most likely on a Rheem.

The Rheem-specific causes we see most

• Failed run capacitor or contactor - the most common no-cool cause on any AC. If the outdoor fan hums but won't spin, this cheap part is usually the fix.
• EcoNet control-board or communication faults on smart-equipped Rheem and Ruud models - the system may report a fault or fail to call for cooling.
• Condenser fan-motor failure - the outdoor fan won't run, so the system overheats and shuts down on hot days.
• Low refrigerant from a leak - shows up as ice on the lines and weak cooling.

See the full list on our Rheem repair page, and our general guide to why an AC stops cooling covers the rest. (Ruud owners: it's the same equipment - here's the Rheem and Ruud rundown.)

When to call a pro

Call a licensed tech if the coil keeps freezing, the outdoor fan won't run, you suspect a refrigerant leak or an EcoNet fault, or the breaker trips repeatedly. Rheem parts are mid-priced and available, so most repairs are quick and reasonable.

Rheem or Ruud AC down today? Get matched with a licensed local pro for same-day repair - upfront pricing, no overtime fees.