BOILER SYSTEM DIAGNOSTICS - Oil Burner Will Not Fire
PROBLEM
POSSIBLE CAUSE
SOLUTION
Not reaching rated pressure
flow
Not activating boiler controls
Correct the fluid problem first - See fluid systems diagnostics
Thermostat on low setting
Thermostat set too low
Set thermostat to an output temperature requiring heating.
No or low fuel in tank
Burner no getting adequate fuel
Check fuel and bring to proper levels. Inspect fuel tank for water or debris.
Low fuel shut-off control activated. Full featured equipment may have a shut off if fuel is low.
No air movement through
stack
No air being supplied
Ensure that the blower is working and that the air band or damper is properly adjusted and in
good repair.
Thermal reset tripped
Press the thermal reset button on burner motor. If the reset trips again an additional problem
must be sought.
Burner motor or capacitor is bad
If motor does not turn, first check thermostat/press switch, the motor starting capacitor and
finally the burner motor itself.
Fuel in the fuel tank
Contaminated fuel in the tank
Ensure that the proper clean fuel is being used. If not, siphon any debris or water from the tank.
Improper fuel in the tank
If the improper fuel is found in the tank, drain and rinse the tank, then fill with proper fuel.
Low fuel shut-off sensor stuck or
faulty
Check the sensor. The assembly may need to be removed to un-stick the float or to replace it
completely.
Water in the fuel filter bowl
Water in fuel supply
Drain water from the tank promptly to prevent rusting. If fuel delivery problems persist, check the
fuel pump for rust.
Debris in the fuel filter bowl
Clogged strainer
If the fuel strainer or in-line filter is clogged, clean or replace.
Clogged fuel nozzle
Replace if there is any evidence of clogging or debris.
Clogged fuel line
Check lines for clogging and clear if necessary.
Water comes out drain at
bottom of tank
Water in fuel supply
Check only if no fuel in the filter bowl - Drain the tank and check for rust. If problem persists, fuel
pump should be checked for rust.
Cannot smell or see fuel at
stack
No fuel being supplied
Check fuel delivery and correct any problems.
No fuel to bleed valve
Air leak to pump
Ensure that air is not entering through the lines or connections.
Broken fuel line
Ensure that the fuel line is connected and is not broken/punctured.
Clogged fuel filter
Check any clogging that exists in the fuel filter
Clogged fuel inlet line
Check any clogging that exists in the fuel inlet line.
Frozen fuel pump
If the fuel pump is frozen it will need replaced.
Broken fuel pump coupling
Check pump coupling if direct or belt driven. Replace or tighten or replace the drive belts if
needed.
