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Billy, Mechanical Contractor
Category: Plumbing
Satisfied Customers: 22678
Experience:  State Licensed Mechanical Contractor
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What causes an oil burner to backfire The system is force

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What causes an oil burner to backfire? The system is force hot water (baseboard) heating.



Is this on start up or shut down?

Customer: replied 7 years ago.
This is while it is operating (starting up when the temperature drops). The furnace is cleaned and maintained by a local plumber/heating service. The furnace is old. When the backfire occurs the door to the furnace is forced open (really old commerical building furnace that was placed in house prior to our purchase).


How often is the backfire occuring?

Customer: replied 7 years ago.
It has happened twice within the last 2 weeks. System was cleaned and checked in September of 2009.


This is a fuel/air problem. The air should be fairly constant. There are numerous things it could be, but the things I would check would be the oil pressure related items.


oil pressure

drive coupling


Once you know the pressure and coupling are good we then have a fixed foundation to start from.

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