Troubleshooting Guide: What to Do If Your Amana PTAC Isn’t Heating or

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I’ll never forget the first time my Amana Distinctions 14,700 BTU PTAC with Heat Pump and 3.5 kW Electric Backup gave me a scare. It was the dead of winter, and the unit stopped blowing warm air. My first thought: Great, I’m going to be out hundreds of dollars for a repair.

But after a little digging, I discovered it wasn’t a major failure at all. It was a simple tripped breaker — something I could fix in minutes. That experience taught me that a step-by-step troubleshooting process can save you time, money, and stress.

In this guide, I’ll walk you through the exact checklist I use when my PTAC isn’t heating or cooling properly. Some issues you can fix yourself. Others require a pro. Either way, you’ll know where to start.

👋 Why Troubleshooting Matters

PTAC units are compact but complex. Inside that box, you’ve got:

A compressor and refrigerant system.
A heat pump and electric resistance heater.
Fans, coils, thermostats, and drainage.

When something goes wrong, it’s not always obvious. But before you call for service, rule out the easy fixes first.

The U.S. Department of Energy estimates that simple maintenance and troubleshooting can prevent 30% of HVAC service calls . That means you can save serious money just by knowing what to check.

🔌 Step 1: Check Power & Basic Settings

Before you assume the worst, start with the basics.

What to do:

Verify power connection:
- Is the unit firmly plugged into the outlet?
- Check the power cord for fraying or damage.
Check the breaker or fuse:
- A 3.5 kW electric heater pulls a lot of amps. Breakers trip if overloaded.
- Reset if necessary, but if it keeps tripping, call an electrician.
Confirm mode and thermostat settings:
- Set to Cool for cooling, Heat for heating.
- Make sure the fan is on Auto or On.
- Thermostat must be set several degrees above (for heating) or below (for cooling) the current room temperature.

👉 Mark’s Tip: Half the time, I’ve found the issue is user error — someone left it in Fan Only mode, or the breaker tripped.

Energy.gov offers a basic troubleshooting checklist here .

🧼 Step 2: Inspect Filters & Airflow

Restricted airflow is one of the most common causes of poor performance.

What to check:

Filters: Dirty filters block airflow, making the unit struggle.
- Remove and clean reusable filters every 30 days.
- Replace damaged or disposable filters.
Blocked vents: Make sure curtains, beds, or furniture aren’t covering the PTAC grille.
Louvers: Adjust louvers for proper air direction.

👉 Lesson I learned: The first time my cooling seemed weak, it was just a clogged filter. Cleaning it restored airflow instantly.

Energy Star emphasizes filter care for efficiency .

❄️ Step 3: Troubleshooting Cooling Problems

If your PTAC won’t cool properly, here are possible issues:

No Cooling at All

Thermostat miscalibrated → Reset or replace.
Compressor not engaging → May require pro diagnosis.
Refrigerant leak → Only a licensed HVAC tech can fix this.

Weak Cooling

Dirty coils → Clean evaporator and condenser coils with a brush or coil cleaner.
Airflow blockage → Clear obstructions and clean filters.
Fan not working → Listen for the fan motor; if silent, it may need replacement.

Unit Runs Constantly

Undersized PTAC → A 14,700 BTU unit covers ~400 sq. ft. max.
Extreme outdoor temps → PTACs can struggle in 95°F+ heat.
Thermostat set too low → Raising it a few degrees helps.

👉 Mark’s Tip: If cooling performance suddenly drops, check the outside grille. Once, mine was blocked by a bird’s nest.

🔥 Step 4: Troubleshooting Heating Problems

Amana PTACs use a dual heating system — a heat pump plus a 3.5 kW electric resistance heater. Understanding when each operates helps narrow down issues.

Heat Pump Mode Not Working

Outdoor temps below ~35°F → The heat pump loses efficiency here; electric backup should kick in.
Reversing valve stuck → Requires a pro to repair.
Coils iced over → Defrost cycle should handle it, but blocked airflow can worsen it.

Electric Backup Heat Not Working

Tripped breaker → Reset and check load.
Faulty heating element → May need replacement.
Thermostat not calling for backup → Confirm setpoint is high enough.

Warm But Weak Airflow

Dirty filter or coil → Clean thoroughly.
Fan motor issue → Listen for odd noises or weak fan spin.

👉 Mark’s Experience: One winter, my PTAC blew only cool air. Turned out the electric heater breaker had tripped. Resetting it fixed everything.

HVAC.com explains heat pump vs. electric backup heating here .

💧 Step 5: Water Leaks or Humidity Issues

PTACs naturally produce condensate in cooling mode. If drainage fails, you’ll notice leaks.

What to check:

Drain pan: Remove and clean out algae or debris.
Wall sleeve slope: Sleeve must tilt slightly outward to drain outside.
Clogged drain: Use a wet/dry vac or pipe cleaner to clear it.

👉 Mark’s Lesson: I once ignored a leak and ended up with water-stained drywall below the PTAC. Regular pan checks prevent costly damage.

Energy.gov’s PTAC guidance highlights drainage as a key step.

🔊 Step 6: Noise & Odor Issues

Strange Noises

Buzzing: Electrical issue or failing capacitor.
Rattling: Loose grille, sleeve misalignment, or fan imbalance.
Grinding/Squealing: Worn motor bearings — call a pro.

Odors

Musty smell: Mold on filters, coils, or in the drain pan. Clean immediately.
Burning smell: Dust on electric heater coils during first use of the season (normal if temporary).
Persistent burning: Shut off power and call for service.

👉 Mark’s Tip: I add a quarterly reminder to clean filters and spray a no-rinse coil cleaner — keeps odors away.