HVAC System Cleaning — Why Ductwork Gets Missed After a Puff Back

This was a puff-back loss where soot and odor traveled through the home while the heat was running. On paper, the claim looked straightforward. In reality, this is where it goes wrong—because the HVAC system becomes part of the loss, and it often gets overlooked.

The Situation

The loss involved:

A puff back from the heating system
Active heat circulating during the event

This allowed:

Soot
Odor

To travel through:

The ductwork system
Multiple areas of the home

What Was Written

The adjuster:

Did not include duct cleaning
Determined there was no need to clean the HVAC system

This was based on:

👉 a field assumption without verification

What Was Missed

What was missed is how puff backs behave when the system is running.

When heat is on:

The HVAC system actively pulls and distributes air
That means soot and odor are pulled into the duct system and spread throughout the house

The ductwork is not separate from the loss:

👉 it becomes part of the contamination

Also missed:

The source unit itself (the heating system that caused the puff back)

That unit requires cleaning and inspection as well

What Most People Miss

You cannot see inside ductwork from the outside.

So assumptions get made:

👉 “If it’s not visible, it’s not affected”

That’s not how this works.

In many cases:

Soot lines the interior of the ducts
Odor gets trapped in the system
Airflow continues to circulate contamination

Proper cleaning may require:

Opening sections of ductwork
Cutting access points to reach full runs
Cleaning the entire system—not just registers

This is part of the system, not an add-on.

What Changed the Outcome

This was proven through field documentation.

Instead of arguing:

Registers were opened
A soot sponge was inserted into the ductwork
The interior was physically wiped on video

The result:

👉 visible soot collected directly from inside the system

That eliminated the assumption.

Once documented:

Full duct cleaning was approved
The HVAC system was recognized as part of the loss

Why This Happens

This happens because:

HVAC systems are often treated as separate from surface damage
Inspections rely on what is immediately visible
Internal contamination is not verified

On paper:

👉 no visible soot = no cleaning needed

In reality:

👉 the system is carrying contamination throughout the home

What Homeowners Should Look For

After a puff back, check:

Was the heat or HVAC system running at the time?
Has the ductwork been inspected internally—not just visually?
Was the source unit evaluated and cleaned?
Is there any odor continuing through vents?

If the system wasn’t tested:

👉 it was likely missed

Takeaway

In a puff-back loss, the HVAC system is not separate—it’s part of the problem.

If soot and odor entered the system, it must be addressed.

This is another example of where:

👉 everything comes down to estimating and documentation

Once the contamination was proven, the decision changed.

One Last Thing (What Everything Comes Down To)

Everything comes down to the estimate.

If your claim is delayed, underpaid, or being pushed back, that’s usually the reason.

If you’re not finding a clear answer to your situation here, go through the other case studies. Most real-world claim problems — and how they were handled — are already shown there.

And if your estimate is in good shape, the other issues tend to be straightforward to push through.

To understand why this happens and how to fix it, review the following:

Why Insurance Claims Get Delayed (It Comes Down to the Estimate): The Real Reason Claims Get Delayed
The Entire Insurance Industry Runs on One Thing That’s Rarely Explained: It’s the Estimate — And This Is Why Contractors Get It Wrong: Contractors Don’t Fail at Building — They Fail at Writing
The Entire Insurance Industry Runs on One Thing That’s Rarely Explained: It’s the Estimate — And This Is Why Adjusters Rewrite Instead of Approving: Adjusters Don’t Approve What They Can’t Follow
The Entire Insurance Industry Runs on One Thing That’s Rarely Explained: It’s the Estimate — And This Is What It Should Look Like: A Proper Estimate Is Not Just a Number

How to Read an Insurance Estimate (Room by Room): Why Most Homeowners Feel Confused by Estimates

How to Vet a Contractor, Public Adjuster, and Mitigation Company: Why This Matters More Than Anything Else

If you still have questions about your claim, visit our Homeowners Insurance Claim FAQs page for quick answers and links to detailed guides.

Learn More At ClaimHelpMe.com

This page explains the basics of how this part of the insurance claim process works.

However, inside ClaimHelpMe.com, homeowners can access real repair estimates, detailed examples, and step-by-step explanations showing how claims are documented, evaluated, and presented to insurance carriers.

The free content explains the fundamentals.
The ClaimHelpMe platform shows how the process actually works.

Explore more homeowner insurance claim guides in our Claim Guides section.

About The Author

Mark Grossman is a Licensed Public Adjuster and NASCLA Certified Contractor with 28 years in the restoration insurance industry and 35 years in construction.

Learn more → Mark Grossman