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It’s Not a Ghost (probably). It’s Your HVAC!

It's not a ghost (Probably) (1)

Is your house haunted? Or is there something more sinister afoot?

Doors slamming by themselves, strange whistling noises, strange drafts, and cool spots. All while no one is home. The house is haunted…right? Well, not so fast. The actual cause of these seemingly paranormal anomalies may be more frightening to your wallet.

If you have been hearing some odd noises around your house lately, it could be that your HVAC system is in need of repair. Here are some noises that indicate it is time to call a professional HVAC technician:

Doors Slamming

One of the tell-tale signs of an evil presence is the infamous door slam. This is often a symptom of air pressure problems caused by poor airflow from HVAC systems. If you have an HVAC positive pressure problem, the air pressure inside your space is too high, and the air is being forced out. This pressure can cause doors opening outward to fly open by themselves, potentially harming people. It also makes inward-swinging doors require super-human strength to open. Equipment problems can lead to positive air pressure. When you have HVAC negative pressure problems, the air pressure inside your space is lower than outside. The pressure difference causes air from outside the space to be sucked in. Causing doors to slam.

What’s the link between negative pressure & HVAC? Both your air conditioner and your furnace have to work harder to counteract the outside air being drawn into the space because of negative air pressure, using more energy in the process.


No, that isn’t a poltergeist dragging chains across the floor, it’s your air conditioning system. The sound of rattling is a symptom of possible debris or loose screws that may have found a way into your ductwork. If you are unable to locate where the rattling is coming from, however, this could indicate a bigger issue that should be addressed quickly before your system is damaged.


Someone or something desperately trying to get your attention? No. Ducts expand or contract with changes in pressure making very literal bumps in the night. If you can’t live with the banging and popping, you have a couple of options:

  • Insulate your ducts: Insulation has noise-canceling properties, but that’s just an ancillary benefit. Duct insulation minimizes heat loss, helping your HVAC operate more efficiently.
  • Replace your ducts: Square ducts are most prone to pop. Circular flex ducts are quieter because they can handle more pressure.


While this might sound like an angry ghost trying to spook you, or a giant snake slithering around just outside of plain view,  it is actually a sign that you are losing air from your HVAC system. A furnace filter not sized correctly or not set right in the chamber creates gaps through which forced air whistles. Try resetting the filter. If you think you have the wrong size, consult the owner’s manual for the specified dimensions. If you aren’t sure, you have may have an air leak within your ducts, check your energy bills. Higher prices and hissing normally indicate a leak.

Hot & Cold Spots

“It’s cold in here”

– Every Ghost Movie Ever

Leaky ductwork can also compromise your indoor air quality and even create hot and cold spots so you want to get this fixed quickly to keep your home comfortable. Hot & cold spots can also be indicative of an airflow issue in your home.

Related: Top 10 Causes of HVAC Airflow Issues


We promise you this sound doesn’t mean you are cursed. It does mean you should take fast action to fix a problem with your system though! Why? Because squealing or screeching means you have a bad belt or motor bearing. You want to address these issues sooner rather than later to prevent damage to your HVAC system.

Screaming or Clanking

A high-pitched screaming could be a sign of a dangerously high refrigerant pressure, a failing compressor, or a faulty blower assembly. Turn off your central air unit immediately and contact an exorcist…ahem…professional HVAC technician.

In Conclusion

An overwhelming majority of strange noises, doors slamming, and cold spots can be explained by your HVAC system. If you’re experiencing any of the strange occurrences listed above, give us a call.

As for the creepy little girl standing behind you while you’re reading this…well… we recommend calling a professional for that.

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Spurk HVAC was formed in 2018 and is located in Warrendale, Pennsylvania. We proudly serve Cranberry Twp., Wexford, Gibsonia, Mars, and the surrounding Greater Pittsburgh area.

We service all makes and models. If you are seeking a heating repairheating system replacementair conditioner repairair conditioning maintenanceair conditioning replacement,  or any other heating & cooling services. Whether you are looking for residential or commercial HVAC services, we look forward to any and all opportunities to become your preferred HVAC contractor.