Fuel System

“ Burner On” lamp does not light after putting “Fire” switch on.

Photo-cell may be sensing external light. Check that it is properly fitted in its socket and that the cap on top is in place. One of the fault indicating lamps may be on. Rectify the fault.

BURNER on lamp lights and flame catches but the unit stops giving alarm.

Photo-cell glass may be dirty, so it does not sense light. Electrical contacts of the photo-cell may be loose. Burner setting and /or air damper may be disturbed, and flame does not sustain. Check fuel pressure.

Flame does not establish, in spite of fuel being sprayed in furnace.

Check that sparking is taking place between electrodes. Remove the burner rod, put the FIRE switch ON & see sparking. Clean the electrodes tips if necessary.(Sparking should not take place between an electrode and diffuser plate.) If flame still does not establish, check burner setting with the burner gauge. Check that air damper setting is not disturbed. In some instances it may be necessary to close the damper slightly while starting. (Restore its original setting after the flame is established).

Fuel is not sprayed after BURNER ON signal.

Check fuel pressure. Check that the burner solenoid valve is functioning. A faint metallic click is heard when it operates.

Fuel pressure does not develop.

Check fuel lamp. Flushing valve of the fuel strainer may be open. Valves on fuel supply line may not be fully open or fuel filters may be locked. If the unit is being fired for the first time or if the fuel line between pump and burner has been emptied of fuel, then air may need to be removed from this line. Take Out the burner rod and hold it upside down (nozzle upward). Take care to contain the spray starts. Repeat this two to three times.

Excessive black smoke.

Check air damper setting. However do not open it too much (beyond its normal setting) to reduce smoke, as it will result in reduced efficiency. Check fuel pressure and spray from nozzle. It should be fine and uniform in all directions. Oil should not drip from sides of the nozzle. Clean the nozzle. Replace if necessary. Check burner setting with the burner gauge. See that nozzle and diffuser plate are concentric. The electrodes should not come within the oil spray zone.

Characterstics of Fuel System

Properties F.O. L.D.O
Density (Approx. kg/lit at 15° C) 0.89-0.87 0.85-0.87
Flash Point, (°C) 66 66
Pour Point (°C) 20


G.C.V.,(kcal/kg) 10,200 10,700
Sediment, %Wt.Max. 0.25 0.1
Sulphur Total, %Wt.Max 4.0


Water Content, %Vol.Max. 1.0


Ash, % Wt. Max. 0.1


The above values are only indicative and may vary from supplier to supplier.