Loud Noises in Spokane, WA

Here's the reality: your AC doesn't make new sounds for no reason. Every abnormal noise points to a mechanical event happening inside the system - something moving that shouldn't be, something failing under load, or a refrigerant issue that's getting worse by the hour.

Banging or clanking usually means a loose or broken component - a fan blade, a connecting rod, or a blower wheel - is hitting something it shouldn't. Every cycle it runs, that component does more damage.

Grinding is often a motor bearing failing. Bearings don't heal. Once they start grinding, the motor is working harder, drawing more current, and heading toward a full seizure. A bearing replacement caught early is a fraction of the cost of a motor replacement caught late.

Squealing points to a worn belt (on older systems) or a failing motor bearing starting its early stages. It's the system telling you something before it gets worse.

Rattling can be as simple as a loose panel screw - or as serious as a failing compressor with internal debris moving around inside the refrigerant circuit.

Hissing or bubbling is a different category entirely. That sound often indicates a refrigerant leak. Refrigerant under pressure escaping through a crack or a loose fitting makes a distinct hiss. If you also notice the air isn't as cold as it should be, that's a strong indicator.

> If you smell something sulfur-like or rotten-egg near your HVAC equipment, stop. That's a possible gas leak - not an AC issue. Leave the home, don't operate any switches, and contact your gas utility or emergency services.

The bottom line: none of these sounds fix themselves. Shutting the system off until we can evaluate it is the right call if the noise is severe.

Understanding what's actually happening inside your system helps you make a better decision. Here's what's behind the most common AC noises.

Compressor Problems

The compressor is the heart of your AC - it pressurizes refrigerant and drives the entire cooling cycle. When it starts to fail, it can produce loud banging, hard starting (a brief loud clunk when the system kicks on), or a persistent rattling from internal wear.

Hard starting happens when the compressor struggles to build pressure on startup. The capacitor - a cylindrical component that gives the compressor motor its starting boost - is often the culprit. A failed capacitor puts enormous strain on the compressor motor every single cycle.

Blower Motor and Fan Blade Issues

The indoor air handler contains a blower motor and wheel that push conditioned air through your ductwork. The outdoor unit has a fan that exhausts heat from the condenser coil.

When a fan blade cracks, bends, or comes loose, it creates an imbalance. That imbalance causes vibration and a rhythmic thumping or rattling that gets worse at higher speeds. Left alone, an unbalanced blade can damage the motor shaft and bearings.

Blower wheel debris is also common in Spokane homes - cottonwood season, dust, and pet hair can pack into the wheel and throw it off balance, creating a persistent rattling or vibration through the vents.

Refrigerant Leaks

Refrigerant travels through a sealed loop of copper tubing and coils. When a leak develops - from a pinhole in the coil, a loose Schrader valve, or a cracked fitting - refrigerant escapes under pressure and produces a hiss or bubbling sound.

Low refrigerant doesn't just reduce cooling performance. It causes the evaporator coil (the indoor coil) to run too cold, which can lead to ice buildup, further restricting airflow and compounding the problem.

Ductwork and Panel Issues

Not every noise comes from the mechanical components. Sheet metal ductwork expands and contracts with temperature changes, which can create popping or ticking sounds. Loose access panels on the air handler rattle when the blower runs. These are lower-urgency issues but worth addressing - loose panels can affect airflow and efficiency.

Before you call, here are a few things you can safely check yourself. These won't diagnose the problem, but they help narrow it down and give us useful information when you call.

• Listen and locate. Is the sound coming from the outdoor unit, the indoor air handler, or the ductwork? Knowing the source helps narrow the cause significantly.
• Check the outdoor unit. Look for visible debris - sticks, leaves, or anything that may have gotten into the fan housing. Don't reach inside. If you see something obvious, shut the system off at the thermostat before inspecting further.
• Check your air filter. A severely clogged filter restricts airflow, which can cause the blower to work harder and produce unusual sounds. If it's visibly dirty, replace it.
• Look at the indoor unit. Check for ice on the refrigerant lines (the insulated copper pipes) or on the indoor coil. Ice buildup is a sign of a refrigerant or airflow problem.
• Note when the sound happens. Does it occur on startup, during operation, or on shutdown? Is it constant or intermittent? This information is useful for diagnosis.

If the noise is loud, metallic, or getting worse - shut the system off and call. Running a failing component to the point of total failure almost always turns a repair into a replacement.