Hansberger Refrigeration Blog: Your AC Repair Resource

Heat Pump Troubleshooting: Making Loud Noises

Heat Pump Troubleshooting: Making Loud NoisesHeat pumps cool by removing heat absorbed by refrigerant in the home and exhausting it outdoors; they heat by absorbing heat outdoors in refrigerant and then carrying it indoors. Heat pumps work especially well in climates with mild winters, so our area is ideal.

If you’re not familiar with heat pumps, you may be baffled by the noises they make. Some are quite normal, like these:

Normal Noises

1. High-pitched squeal at startup. Some units do this until pressures inside the unit adjust.

2. Humming/buzzing. This is usually not a problem, and indicates the outdoor unit reversing valve solenoid coil is energized. Some units have louder valve noises than others.

3. Tapping/clicking. This can be a normal startup noise.

4. Vibrating/rattling. This can be a normal startup noise.

5. Whooshing. When the heat pump goes into defrost mode, it can make a whooshing sound, followed by a compressor noise. These are usually the result of a momentary internal pressure adjustment as the refrigerant changes direction of flow.

More Worrisome Noises

The following noises may present more of a problem than the ones listed above.

1. Hissing. Usually indicates a refrigerant leak. Call a technician right away.

2. Squeal. This could mean the motor is going bad.

3. Buzzing/Hum. A buzz when the system isn’t running may mean there’s a stuck relay or contact, motor issues or a faulty capacitor.

4. Gurgling. Low refrigerant charge. Get it fixed right away.

5. Clanking. Most often, a frayed fan belt.

6. Popcorn or tumbling rocks sound. Several potential causes possible, but requires attention right away.

7. Grinding. Likely lack of lubrication or dirty components.

8. Shrieking. Possible bad compressor. Shut it down immediately. Dirty motor bearings can also create loud noises.

9. Metal on metal. Possibly fan blades hitting ice chunks, other components or loose wires. Turn the system off.

Your comfort is important to us. For service or repairs, maintenance or upgrades, contact Hansberger Refrigeration and Electric Company of Yuma.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 928-723-3183.