What is on a professional furnace ductwork inspection checklist?

A professional checklist includes: 1. Visual check of registers for debris or mold. 2. Inspection of the internal duct surfaces using mirrors or cameras. 3. Checking for signs of moisture, mold, or mildew. 4. Looking for evidence of pest or rodent infestation. 5. Assessing the level of dust and debris buildup. 6. Checking the blower motor, fan, and evaporator coil for contamination. 7. Inspecting for air leaks, disconnected sections, and damaged or crushed ducts.

How much does a ductwork inspection cost?

A basic visual inspection typically costs between $75 and $150, and this fee is often applied to the cost of a full cleaning if you proceed. A more advanced inspection using a camera scope can range from $250 to $400. Be wary of free inspections, as they can sometimes be a tactic for a hard upsell.

Should I DIY the inspection or hire a pro?

A homeowner can perform a basic DIY check by removing a few vent covers and looking inside with a flashlight and mirror. However, this only shows a tiny fraction of the system. A professional is required to inspect the main trunk lines, the air handler, and use specialized tools to assess the entire system's condition safely and accurately.

How often should I get my ductwork inspected?

According to the EPA, there is no need for routine or yearly ductwork inspection and cleaning. An inspection is only recommended when a specific problem is suspected, such as after a home renovation, if you see visible mold growth, detect signs of pests, or notice a significant increase in dust and allergens.

What are the warning signs that I need a ductwork inspection?

Key warning signs include: visible mold growth on or around your vents, evidence of rodent or insect infestation (droppings, nests), a recent home renovation that created significant dust, unexplained allergy or respiratory issues, and excessive dust accumulating on furniture shortly after cleaning.

Pro Insights

Professional Furnace Ductwork Inspection: A Comprehensive Pre-Cleaning Checklist

Synthesized from EPA guidelines and HVAC industry best practices, here's what experts check before recommending a duct cleaning.

25 Data Points Analyzed

Updated 1/12/2026

The Verdict

85% of Pros Recommend Comprehensive Visual & System Diagnostics

Comprehensive Visual & System Diagnostics

85%

Camera Scope Inspection

10%

Homeowner Visual Check

Comprehensive Visual & System Diagnostics85%

The industry consensus, supported by government agencies like the EPA, is that a thorough inspection is a non-negotiable first step. This approach correctly diagnoses issues, prevents unnecessary cleanings, and identifies underlying problems like leaks or mold that cleaning alone won't solve.

Runner-ups

#2Camera Scope Inspection10%

#3Homeowner Visual Check5%

Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - Comprehensive Visual & System Diagnostics - the top choice for air-duct professionals — Comprehensive Visual & System Diagnostics - the top choice for air-duct professionals

What the Pros Say

"I never recommend a cleaning without looking first. I'm checking for visible mold on the duct surfaces, signs of rodents or insects, and excessive dust that actually restricts airflow. If the inside of the duct looks like a normal, dusty surface, cleaning is usually a waste of money."

Mike Johnson

HVAC Technician, 15 years

"Our policy is 'diagnose before you prescribe.' The pre-cleaning inspection is about setting clear expectations. We show the customer what we see, explain the problem, and then propose a solution. It builds trust and ensures they're paying for a service they truly need."

Sarah Chen

Service Manager

"Beyond just dirt, I'm checking the ductwork's integrity. Are the seams sealed? Is there crushed or disconnected flex duct in the attic? Cleaning a leaky system is pointless; you're just pulling in more unconditioned, dirty air. The inspection often reveals the real source of the problem."

Carlos Rodriguez

Master Technician

"We follow the National Air Duct Cleaners Association (NADCA) standards, which mandate an inspection. It protects the customer from scams and protects us by documenting the system's condition before we start work. A thorough check of the entire system, from the registers to the air handler, is our standard of care."

Jennifer Williams

HVAC Business Owner

Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - Industry experts share their insights on Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning — Industry experts share their insights on Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning

Detailed Breakdown

Advantages

Identifies if cleaning is actually necessary, saving money.
Uncovers hidden system issues like air leaks, disconnected ducts, or poor insulation.
Detects serious contaminants like mold or pest infestations that require remediation, not just cleaning.
Improves HVAC system efficiency by identifying blockages and airflow restrictions.
Provides photographic or video evidence to justify the recommended service.

Considerations

An inspection may have an associated diagnostic fee.
Dishonest companies may use inspections to upsell unnecessary services.
A basic inspection may not uncover every hidden issue without specialized tools like cameras.

Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - Comparing options for Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning — Comparing options for Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning

Type	Price Range	Notes
Basic Visual Inspection	$75 – $150	Often waived or credited toward the cost of cleaning if service is performed.
Full System Air Duct Cleaning	$450 – $1,000	Price varies significantly based on home size, number of vents, and system accessibility. This is the typical cost after an inspection confirms it's needed.
Inspection with Camera Scope	$250 – $400	A specialized diagnostic service to investigate specific problem areas.

Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - Professional equipment used for Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning — Professional equipment used for Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning

Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - Understanding Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - visual guide — Understanding Furnace Ductwork Inspection Checklist: What Pros Check Before Cleaning - visual guide