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Why Is My Boiler Smoking?

Puffbacks in Boilers

When your oil boiler begins to smoke, it should be repaired immediately. This smoke is called a “puffback” and is caused by excess oil in the combustion chamber. Knowing why the boiler is smoking is important so you can properly repair it.

Preventing Puffbacks in Boilers

When the boiler shuts down, excess oil that was previously compressed will cool down and expand. This oil will be forced out of the burner nozzle and into the combustion chamber. When too much of it builds up here, it can explode which will cause a loud noise and the “puffback.”

You can take the following steps to prevent boiler puffbacks:

  1. Look for Leaks – If the area underneath the oil supply has a collection of oil, service all of the piping and connections. When the oil leaks out, air will take its place within the lines. This air will worsen the leak at the burner nozzle when the boiler is shut down. Servicing your boiler yearly can help prevent this from happening.
  2. Change the Filter in the Fuel Supply – Be sure to change the filter in the fuel supply as a part of routine maintenance. When the boiler is serviced by a professional each year, have the technician clean the fuel shutoff valve. This valve needs to be cleaned because if not, the boiler will not shut down right away. It will linger on for longer than normal, allowing excess oil to be forced through the burner nozzle.
  3. Clean Out the Burner Nozzle – If this nozzle is even just slightly blocked, some oil will fail to combust. It will end up in the combustion chamber where it will explode, creating the noise and “puffback.” Having a pro clean out this nozzle during maintenance can prevent this from happening as well.

Explore Our Boiler Services

A smoking boiler is one that needs to be serviced as soon as possible. Waiting to do this can cause damage to your boiler, shortening its lifespan. When you notice your boiler smoking, grab the phone and contact the pros at Tri-City Heating and Cooling.

To learn more, or to schedule a service, give us a call at (203) 303-5700.

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