Soot Without Fire: The Anatomy of a Puff Back

At PuroClean Home Emergency Services we tackle all sorts of jobs in the Madison and Southern Indiana area. One of the more unique type of jobs is a “Puff Back”. Most people have never heard of a “puff back” until they have one.

What is a “puff back”?

A “puff back” is a sudden release of smoke and soot from a furnace or boiler. The most common cause is when the ignition process fails (lighting the flame that heats the boiler) to properly ignite fuel (gas or oil), causing a buildup of gas vapors that then combust explosively when ignition finally happens. Think about your propane grill, If the ignition misfires and the propane builds up sometimes you can get a small” explosion” when it finally lights. In the case of a boiler this explosion can cause soot or smoke into the home instead of through the flue. This is referred to as “puffing back”

The most common heating system in our small town of Madison Indiana is the heat pump, but there are
still many gas or oil burning boilers. Boilers heat up water that is then either circulated through
radiators throughout the home, or through an air exchanger and distributed through a forced air system. Although “puff backs” happen mostly in boilers that are attached to a forced air heating system, they can happen on all systems.

How Does It Spread?

A forced air system utilizes a large blower to draw air over the heating element and push it out to the
home using ducting and registers. When you have a puff back in the system, it draws in all of the smoke and soot caused by the explosion then pushes it out through the ducts and into the home.
When this happens, soot gets distributed throughout the home and lands on all of the surfaces. This
soot can contain carcinogens that can be dangerous to a person’s health. Similar to soot from a fire,
it requires a cleaning protocol that most people are not familiar with and should be remediated by a
professional cleaning company like PuroClean.

How To Clean a “Puff Back”

The cleaning process is very similar to the cleaning after a fire. Our PuroClean cleaning technicians will assess the overall soot levels and proceed with measures including HEPA vacuuming, dry sponging the surfaces and then cleaning with our propriety cleaning and deodorizing solution. Depending on the severity deodorization may also be required.

Other Ways “Puff Back” Can Happen

Another area that can have puff Backs is a chimney. Chimney puff back can be caused by the build up
of creosote restricting the proper venting of smoke from fires, other restriction such as bird nests or
changes in air flow caused by remodeling.

Recently we encountered a situation in the Madison area that was even very unique with us. We had a
customer call after having a large amount of soot (almost a 55-gallon barrel full) fall out of a chimney
that was no longer in use and had been removed above the roof level during a remodel the previous owner. Something happened to change the dynamic in the remaining chimney and
the soot fell and forced a piece of cardboard fitted to “seal” the chimney out and deposit the soot on
the floor. When this happened, it got into the air system and spread throughout the house requiring
cleaning on almost all the surfaces in the home.

Suffice it to say this type of “puff back” doesn’t happen often but goes to show almost any scenario is
possible.

The staff here at PuroClean has been trained to help identify and provide cleaning solutions for soot deposits no matter how they get there. PuroClean Homer Emergency Services –
Water/Fire/Mold/Biohazard