Troubleshooting Guide: Common Amana 12k Through-the-Wall AC Problems 

By Jake — the guy who gets called after the YouTube tutorials fail, after the “maintenance guy” tightens the wrong screw, and after the hotel manager says, “Jake, room 214 is making a sound like it’s possessed.” I’ve fixed hundreds of Amana through-the-wall units — everything from dead compressors to angry rattles to water pouring down drywall like a waterfall.

This is the no-nonsense, step-by-step troubleshooting guide for the most common problems with Amana 12,000 BTU through-the-wall (TTW) AC units. I’ll tell you what causes each issue, how to diagnose it, and what you can fix yourself — plus when to call someone like me.

Let’s get practical.

---

1. Problem: No Cooling (Unit Blows Warm Air or Not Enough Cold Air)

If your Amana 12k isn’t cooling, the cause is almost always airflow, refrigeration, electrical, or thermostat-related. Here’s how to isolate the issue.

---

1.1 Basic Checks (Do These First)

Before diving into tools, verify:

• Thermostat is set to Cool

• Temperature is set at least 5°F below room temp

• Fan is not set to Fan Only

• Fresh-air damper (if equipped) is not open

• The filter is not clogged

• Coils are clean

Dirty coils alone cause 60–70% of “no cooling” service calls in my experience.

Proper cleaning instructions are available from Amana here:
Amana HVAC Resources – https://www.amana-hac.com/resources

---

1.2 Airflow Obstructions (Most Common Cause)

Symptoms:

• Weak airflow

• Air feels cool near coil but warm at grille

• Frost on evaporator coil

Causes:

• Dirty filter

• Dirty indoor coil

• Dirty blower wheel

• Crushed or blocked sleeve

• Blocked outdoor grille

Fix:

1. Clean filter

2. Vacuum indoor coil

3. Inspect and clean outdoor grille

4. Ensure sleeve is not crushed or blocked

---

1.3 Low Refrigerant (Less Common but Serious)

TTW units are sealed systems. If the refrigerant is low, it means a leak.

Symptoms:

• Hissing at coil

• Ice forming on evaporator

• The compressor runs constantly

• Air lukewarm

Fix:

You cannot repair this yourself.
Call a pro — sealed systems require EPA-certified work.

EPA refrigerant handling guidelines:
EPA Refrigerant Regulations – https://www.epa.gov/section608

---

1.4 Thermostat or Control Board Problems

If compressor never turns on:

• Faulty thermostat sensor

• Loose wiring harness

• Bad control board

Fix:

• Reseat harness connections

• Reset unit by unplugging for 5 minutes

• If still faulty → Board replacement required

---

1.5 Voltage Issues

Amana 12k TTW units run on 208/230V. Low voltage = poor cooling.

Symptom:

Compressor hums but won’t start.

Tools:

Voltmeter (only if you know how to use one safely).

Voltage safety and wiring reference:
NFPA NEC Electrical Code – https://www.nfpa.org/NEC

---

2. Problem: No Power (Unit Is Dead, No Lights, No Response)

This problem is almost always electrical — outlet, breaker, plug type, or internal fuse.

---

2.1 Check the Power Source

Steps:

1. Verify outlet has power by testing with another appliance

2. Check breaker panel for a tripped breaker

3. For 230V units, ensure both poles of the breaker are engaged

---

2.2 Check the Power Cord & Plug Type

Amana TTWs use specific 208/230V plug types:

• 6-15P or

• 6-20P

Wrong outlet = no power.

---

2.3 Check Internal Fuse (Most People Don’t Know These Exist)

Behind the control panel is a small fuse that protects the internal electronics.

Fix:

• Remove front cover

• Access fuse panel

• Replace blown fuse (same rating only)

If the fuse blows again → electrical short or board problem.

---

2.4 Control Board Failure

If power reaches the board but nothing lights up, the board is dead.

Fix:

Replace the main PCB.

---

3. Problem: Rattling Unit (The Most Annoying Failure)

A rattling Amana TTW is almost always installation-related, not mechanical failure. Here’s how to narrow down the source.

---

3.1 Loose Sleeve or Chassis Fit

If the sleeve isn’t square or the chassis isn’t fully seated:

• The compressor vibration amplifies

• You get a rattling or buzzing sound

Fix:

1. Ensure chassis rails align fully

2. Tighten sleeve mounting screws

3. Add rubber isolation pads

4. Add non-hardening foam to remove side gaps

Noise reductions from proper sleeve sealing are significant.
Great reference here:
Alpine Amana Sound Testing – https://documents.alpinehomeair.com/product/Amana%20PTAC%20Sound%20Report.pdf

---

3.2 Loose Front Grille

This is extremely common.

Fix:

• Tighten grille screws

• Replace missing foam at grille edges

• Add shims where plastic vibrates

---

3.3 Blower Wheel Out of Balance

If blower wheel is dirty or loose, it wobbles.

Fix:

1. Clean wheel

2. Tighten set screw

3. Replace if cracked or warped

---

3.4 Compressor Vibration Transfer

If the compressor is touching the frame or sleeve:

Fix:

• Add rubber washers

• Adjust screw tension

• Ensure sleeve is level side-to-side and pitched outward properly

---

3.5 Fan Motor Bearings Worn Out

Not common until year 6–12.

Fix:

Replace motor.

---

4. Problem: Water Leaks (Inside or Outside)

Water leaks are always drainage or airflow problems — not a “bad AC.”

---

4.1 Sleeve Not Pitched Properly (Most Common)

The sleeve MUST tilt outward ¼ inch.

If pitched inward or level:

• Water flows inside

• Pan overflows

• Mold forms

• Unit leaks down the wall

Fix:

Reinstall the sleeve with the correct pitch.
Full pitch instructions available via Amana documentation:
Amana Install Guides – https://www.amana-hac.com/resources

---

4.2 Drain Port Blocked

Drain holes clog from:

• Dirt

• Bugs

• Rust

• Debris

• Paint

Fix:

• Open back grille

• Clear drain holes with pipe cleaner or small brush

---

4.3 Indoor Coil Frozen

If coils freeze, water dumps when it melts.

Causes:

• Dirty filter

• Low refrigerant

• Blocked airflow

Fix:

• Clean filter

• Clean indoor coil

• Let unit thaw

• If re-freezes → low refrigerant → call pro

---

4.4 Negative Air Pressure in Room

Bathroom fans or exhaust fans can pull water indoors.

Fix:

Seal sleeve perimeter to reduce infiltration.
Weather sealing basics:
Energy.gov Weatherization – https://www.energy.gov/energysaver/weatherize

---

5. Problem: Remote Control Issues (Unresponsive or Inaccurate)

If your Amana remote stops working or loses connection, here’s how to fix it.

---

5.1 Batteries (Obvious but Common)

Replace with fresh alkaline batteries.
Weak batteries often still light the remote but fail to send IR signal.

---

5.2 Blocked Sensor on AC Unit

Dust, dirt, or labels can block the signal.

Fix:

Wipe sensor area with microfiber cloth.

---

5.3 Remote Out of Sync

Sometimes the remote stops pairing with unit.

Fix:

1. Unplug AC for 3 minutes

2. Remove batteries from remote

3. Reinstall batteries

4. Plug AC back in

---

5.4 Remote IR LED Failure

Rare, but it happens.

Fix:

Replace remote.
(They’re cheap and easy to replace.)

---

6. Problem: Thermostat Errors or Incorrect Temperature

The Amana control board uses a thermistor (temperature sensor) that can fail or drift. Incorrect temperatures lead to short cycling or no cooling.

---

6.1 Thermistor Out of Position

If the sensor touches the coil, readings are inaccurate.

Fix:

Mount sensor in proper clip location — not touching metal.

---

6.2 Dirty Sensor

Dust insulates sensor → delays readings.

Fix:

Clean gently with isopropyl alcohol.

---

6.3 Failed Thermistor

If resistance reading is wrong at room temperature:

Fix:

Replace thermistor (cheap part, easy swap).

---

6.4 Control Board Misreading Sensor

Sometimes the board is the problem.

Fix:

Replace control board.

---

7. Full Troubleshooting Table (Jake’s Field-Ready Cheat Sheet)

---

8. Preventative Maintenance (Jake’s “Do This Twice a Year” List)

If you maintain your unit correctly, 90% of problems never appear.

• Clean filter monthly

• Clean coils twice per year

• Ensure sleeve pitch is correct

• Check the outdoor grille for debris

• Tighten screws and inspect gaskets

• Check drain holes annually

• Inspect the thermostat sensor

Clean coils & filters improve both performance and lifespan. For general HVAC maintenance guidance:
Energy Star HVAC Maintenance – https://www.energystar.gov/products/heating_cooling

---

Conclusion

Most Amana 12k TTW issues are simple, mechanical, and preventable.
If you understand how these systems work, you can diagnose:

• No cooling

• No power

• Rattles

• Water leaks

• Remote failures

• Temperature errors

…without spending hundreds on unnecessary service calls.

Jake’s Hard Truth:

80% of the units I fix were installed wrong, not broken.
And 90% of the remaining failures were preventable with basic cleaning.

Follow this guide and your Amana through-the-wall unit will run longer, quieter, colder, and with fewer headaches.

This has been Practical Jake — the guy who fixes ACs after everyone else gives up.

In the next blog, you will learn about Maintenance Checklist: Get 10–15 Years Out of Your Amana Through-the-Wall AC