Limited Time: Waived diagnostic with approved repair◆🔥 FREE replacement estimates◆📞 Call (209) 216-7240 — Same-week service◆⚡ Schedule online · Honest, family-owned◆🛠️ Licensed · Insured · Family-owned◆ Limited Time: Waived diagnostic with approved repair◆🔥 FREE replacement estimates◆📞 Call (209) 216-7240 — Same-week service◆⚡ Schedule online · Honest, family-owned◆🛠️ Licensed · Insured · Family-owned◆
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Strange HVAC Noises
Banging, screeching, hissing — what each sound actually means.
Call (209) 216-7240Symptoms you're seeing
- Loud bang at startup or shutdown
- Continuous screeching or squealing
- Hissing from refrigerant lines or coil
- Rattling or buzzing from outdoor unit
- Grinding or scraping from indoor blower
What's actually causing it
CommonFailing blower motor bearings (squeal/grind)
CommonLoose blower wheel or fan blade (rattle/bang)
CommonRefrigerant leak (hissing)
PossibleFailing compressor (loud humming + buzzing)
PossibleLoose ductwork or expansion noise (popping)
What to do right now
- 1Note WHEN the noise happens — startup, runtime, or shutdown
- 2Note WHERE — outdoor unit, indoor blower, or in the ducts
- 3Shut the system off if you hear loud grinding or metal-on-metal
- 4Don't ignore hissing — refrigerant leaks damage the compressor and pollute the home
When to call us
Soonest available appointment. Most noise complaints catch problems at the cheap-fix stage. Ignored, they become compressor or motor replacements.
Estimated cost
$185 diagnostic + $200–$1,200 repair depending on root cause.
We fix this in your town
Same-week service across the Central Valley.
FAQs
Is buzzing dangerous?
Electrical buzzing (transformer, contactor) can be — get it diagnosed within a day. Mechanical buzzing usually isn't immediate but worsens fast.
Is hissing always a refrigerant leak?
Usually, yes. Could also be a duct pressure leak, but coil/lineset hissing is refrigerant 90% of the time.