As the weather gets colder and home-owners start up their heating systems forthe first time in months, insurance carriers see an influx of claims for the failureof furnaces and boilers. One frequentissue that can be both messy and potentially dangerous is a phenomenon knownas a “puffback.”
A puffback is a release of smoke or sootthat occurs when a boiler or furnace misfires. It is important that adjusters and insurance carriers understand what a puffback is and what causes one to occur. Notonly are they expensive (and occasionallydangerous), but they are often caused by anon-covered cause of loss. (Figure 1)
What is a puffback?
A puffback occurs when a furnace orboiler does not ignite properly and allowsoil or gas vapors to build up within theignition/combustion chamber. When itdoes finally ignite, the excess fuel in thechamber causes this puffback scenario.The result can be anywhere from a smallamount of smoke to a minor explosion,depending on how much fuel has accumulated in the chamber. (Figure 2)
Puffbacks can occur in both oil andgas furnaces and boilers, but are muchmore common in oil-fired equipment.Oil furnaces and boilers require moremaintenance than their gas-fired counterparts, presenting more opportunitiesfor the ignition process to be hinderedif the system is not properly maintained.Additionally, oil is less likely than gas todissipate, leading to larger average explosions. Forced air, oil-fired heating systempuffbacks tend to be the messiest, as oilcreates more soot than gas, and the ductwork for the forced air system can spreadthat soot to every room in the home.
What causes a puffback?
Regardless of fuel type, furnaces andboilers should have annual system main
Furnace and Boiler Puffbacks
Soot damage froma puffback.
Damage caused by a puffbackto an oil-fired furnace.
Clogged flue pipe that lead to apuffback in an oil-fired boiler.
Puffback sootdamage withinthe heat chamberof a boiler.