HVAC Oracle
KEYWORDS:
PART #:  
Home  |  Contact Us  |  Ask the Oracle  |  Parts  |  Service  |  Equipment  |  VIEW Cart  


Service Content

Oil Burner Flame Failure
Scotty McGregor
HVAC Oracle

 
2005-07-11  

After the oil burner starts the flame may or may not light right away and the flame safety control trips after 30 or 45 second timing period. This occurs when the flame safety control does not receive a flame signel from the infrared scanner. There are a number of possible causes an we have only listed the most common here.

Dirty Oil Nozzle
If the burner does not light it may be caused by a dirty nozzle. The shape and the size of the spray pattern from the oil nozzle is critical to the burners operation. Wear in the nozzle's spinner or nozzle or a build-up of dirt around the opening of the nozzle will cause a irregular spray pattern. The nozzle should be replaced annually for best efficiency.

Oil Pump

The spray pattern of the oil nozzle requires a steady supply pressure of 100# to create a stable spray cone. If the pressure is too low, too high or is fluctuating in pressure will cause the flame to be unstable or fail to lite. Use a pressure gauge on the fuel unit test port. Adjust as required

Fuel/Air Ratio

Oil burners use a fan to provided the air for combustion. There is an adjustable air inlet on the burner that only requires very small adjustments. Check the opening of the air intake. It can be restricted with lint and dirt which can be wiped away or cleaned with a vacuum. Very small changes can have a big effect on the fuel/air mixture. Too much air or too little will create an unstable flame. The air should only be adjusted while using an smoke tester or a combustion analyzer. If the burner is short of air it will rumble and produce soot and high levels of CO. Too much air will sharply drop the efficiency of the burner and increase you operating costs.

Ignitor Position

Check with the manufacturer of the burner for the recommended positioning and gap setting for your burner. Many burners will function with the points of the ignitors 1/2" above the nozzle opening, 1/8" forward of the nozzle face with and 1/8" gap between the points.

Do not reset the flame safety control more then twice. Each time the oil pump runs oil is being sprayed into the combustion chamber. This is a fire and explosive hazard. The oil will build up and can ignite all at once when the burner is repaired.



More Information
Change of Season
Spring and fall are a challenge for your equipment to maintain comfort in the building

Crackacked Heat Exchanger
This is one I always hated telling the customer, "You have a cracked heat exchanger and your furnace has to be replaced,...Today."

My Furncycleace burner cycles on and off
There two things that normally cause burner short cycling

Oil Burner Flame Failure
Oil burners will shut down and require a manual reset.

Residential boiler maintenace
September is the time to get your boiler ready for the winter.