Loud Noises in Spokane Valley, WA

Here's the reality: your AC doesn't make new noises for no reason. Something mechanical has changed - a part is failing, something has come loose, or a component is running under stress it wasn't designed to handle.

The risk of waiting isn't just comfort. It's cost.

A rattling panel that costs almost nothing to fix today can become a cracked heat exchanger or a seized compressor if ignored for a season. A squealing belt or bearing that's easy to replace now can fail completely mid-July, when every HVAC tech in Spokane Valley is already booked out.

A few specific sounds carry safety implications:

• Hissing or bubbling can indicate a refrigerant leak. Refrigerant is a pressurized chemical. A slow leak reduces cooling efficiency and can damage the compressor - the most expensive single component in your system.
• Burning smells paired with noise may point to an electrical issue or overheating motor. If you smell burning, shut the system off at the thermostat and call immediately.
• Grinding or metal-on-metal sounds often mean a bearing or motor is failing. Running the system in this state can cause secondary damage to surrounding components.

The dirty secret is that most homeowners wait too long because the AC is still "kind of working." By the time it stops working entirely, a repair that could have been $200–$400 has turned into a compressor replacement or full system swap.

Spokane Valley has seen significant residential growth over the past two decades. A lot of that housing stock - neighborhoods near the Spokane Valley Mall area, out toward Greenacres, and along the Centennial Trail corridor - was built with builder-grade HVAC equipment. Those systems are now 15 to 20 years old and hitting the end of their designed lifespan. Components wear out. Fasteners loosen. Motors fatigue.

Here's a breakdown of the most common causes by sound type:

Banging or Clanking This usually means something has come loose inside the unit - a fan blade, a motor mount, or a blower wheel. In outdoor condenser units, debris (sticks, rocks, hail damage) can also cause impact sounds. A loose component that's still spinning can cause rapid secondary damage.

Rattling Rattling at startup or shutdown often points to loose panels, screws, or ductwork connections. It can also indicate a failing capacitor - the component that gives the compressor and fan motors their starting voltage. A weak capacitor causes motors to strain and vibrate before reaching full speed.

Squealing or Screeching This sound typically comes from one of two places: a worn fan belt (on older systems with belt-driven blowers) or a failing motor bearing. Bearings are small metal rings that allow shafts to spin smoothly. When they wear out, metal contacts metal - and you hear it clearly.

Grinding Grinding is a step beyond squealing. It means a bearing has failed significantly, or debris has entered a motor housing. At this stage, the motor itself is at risk. Running the system in this condition can destroy a motor that might otherwise have been serviceable.

Hissing or Bubbling These sounds point to refrigerant. Hissing usually means refrigerant is escaping under pressure from a leak in the line set or coil. Bubbling or gurgling can indicate refrigerant moving through a section of the system where it shouldn't be - often a sign of low charge or a leak that's already caused refrigerant loss.

Clicking (Repeated, Not Just at Startup) A single click at startup and shutdown is normal - that's the relay engaging. Repeated clicking during operation usually means the system is trying to start and failing. This points to a failing capacitor, a failing contactor (the electrical switch that powers the compressor), or a compressor under stress.

Before you call - or while you're waiting - there are a few safe checks you can do yourself. These won't fix the problem, but they help narrow things down and rule out simple causes.

1. Check your air filter. A severely clogged filter forces the blower motor to work harder, which can cause vibration and noise. If it's visibly gray and packed, replace it with the correct size filter for your system.

2. Walk around the outdoor condenser unit. Look for visible debris - branches, leaves, or hail damage - that may have entered the unit. Do not reach inside the unit. If you see something obvious, note it for the technician.

3. Check the panels on the outdoor unit. Loose access panels rattle. If a panel is visibly out of place or a fastener is missing, that's worth noting.

4. Listen for where the sound is loudest. Is it coming from the outdoor condenser, the indoor air handler, or the ductwork? This helps localize the problem before we arrive.

5. Note when the sound happens. At startup only? Continuously during operation? At shutdown? This timing is diagnostic information.