let’s start with the basics!

Maintaining an HVAC system is essential for keeping your home comfortable, efficient, and safe year-round. Regular upkeep includes changing or cleaning air filters every one to three months, checking thermostat settings for proper operation, and keeping outdoor units clear of debris to ensure proper airflow. It’s also important to inspect ductwork for leaks, listen for unusual noises. By staying proactive with maintenance, you can extend the life of your system, improve indoor air quality, reduce energy costs, and avoid unexpected breakdowns.

Maintaining a home HVAC system requires a handful of reliable tools to keep everything running smoothly and safely. Basic items like a screwdriver set, adjustable wrench, and pliers help you access panels and tighten connections. A vacuum or shop vac is useful for removing dust and debris from around the unit, while a soft brush or coil-cleaning tool helps clean evaporator and condenser coils. You may also need a level to ensure the outdoor unit sits properly, a flashlight for inspecting hard-to-see areas, and replacement air filters for routine upkeep. For more advanced maintenance, tools like a multimeter for checking electrical components or a refrigerant gauge set should be used carefully—and typically only by trained professionals. Having the right tools on hand makes simple HVAC care easier, safer, and more effective.

Below i will list some tools you may want to consider investing in before trying to work on any hvac system!

Now that we have the basics let’s talk about changing your home air filter!

In most home HVAC systems, you’ll find the air filter in one of three common locations. Here’s how to figure out where yours is:

1. At the Return Air Vent (Most Common in Homes)

Look for the large grille inside your home—usually in a hallway, ceiling, or wall.

If the grille is bigger than a normal supply vent (often 16x20, 20x20, 20x25, etc.), it likely hides the filter.

• Open the grille with the thumbscrews or latches

• The filter will be sitting right behind it

2. At the Furnace or Air Handler (Inside Closet, Attic, Basement, or Garage)

If your system uses a furnace or a central air handler, the filter may be near the blower:

• Look on the side, bottom, or top of the unit where the return duct connects

• There’s often a small slot or door labeled “Filter,” where the filter slides in and out

• This is common for vertical units in closets or horizontal units in attics

3. Inside the Return Plenum (Less Common)

Some older or custom systems place the filter inside the large metal box attached to the furnace:

• You may see a small metal door or panel with screws

• Behind it will be the filter, directly before the blower motor

With your air filter changed let’s talk about checking basic electrical components for wear

Before you begin, turn off power at the breaker to both the indoor and outdoor units. Electricity in HVAC systems can be dangerous even when the unit appears off.

1. Inspect the Thermostat

• Remove the thermostat cover.

• Look for loose wires, corrosion on terminals, or dust.

• Make sure the screen is clear, buttons work, and settings respond.

• Replace batteries if it uses them.

2. Check Electrical Connections

• With the panel removed (power OFF), examine wiring inside the air handler and outdoor condenser.

• Look for:
  

  • Loose or frayed wires

  • Burnt or discolored insulation

  • Melted connectors

  • Corrosion around terminals

• Gently tighten any clearly loose screw-type connectors (don’t overtighten).

3. Examine the Capacitors (Common Failure Point)

• Capacitors help motors start and run. When failing, they show visual signs.

• Look for:
  

  • Bulging or swollen top

  • Leaking oil

  • Burnt smell

  • Rusted or corroded terminals

• If you see any of these, the capacitor should be replaced.

  Look in my products page to find the capacitor you need. If it’s not in there please email me.

  4. Inspect Contactors (Outdoor Unit)

• Contactors control power flow to the compressor and fan.

• Warning signs of wear:
  

  • Pitted or burnt contacts

  • Buzzing or chattering noise when the system runs (with power back on)

  • Sticking contacts

• If the surface looks badly burnt or uneven, replacement is needed.

  Look in my products page to find the contractor you need if it’s not in there please email me!

5. Check the Blower Motor and Fan Motor Wiring

• Look for:
  

  • Loose mounting screws

  • Wires touching moving parts

  • Heat damage or melted wire insulation

• Spin fan blades by hand (with power off) — they should rotate smoothly without grinding.

6. Inspect Fuses

• Most systems have cartridge fuses near the air handler or outdoor disconnect.

• Look for:
  

  • Burn marks

  • Broken filament (visible in glass fuses)

  • Loose connections in the fuse holder

7. Look for Signs of Overheating

Anywhere electricity flows, you want to check for:

• Burnt smells

• Heat discoloration (brown or black marks)

• Melted plastic near relays, wires, or boards

• Scorch marks inside the panel

These signs almost always mean a component is drawing too much current.

8. Check Circuit Boards

• Most modern HVAC systems have a control board inside the furnace/air handler.

• Look for:
  

  • Burnt components

  • Broken solder points

  • Corrosion

  • Blinking error codes (after power is back on)

    9. Test with a Multimeter (If You’re Comfortable)

If you know how to use one safely, you can:

• Test capacitance on capacitors

• Test voltage at the contactor and thermostat wires

• Check continuity on fuses

If you’re not confident, stop at the visual inspection steps.

Here are some tools to help with checking electrical components

Along with all the same tools from the previous section you will want to add these items to your tool bag!

For more in depth guides head over to my guides page in the pull down tab!