Heater smokes

Step 1: Exhaust pipe

Check exhaust pipe for damage (cross section reduced)

Possible defect Remedy
Mechanical damage Install new exhaust pipe
Partially blocked Clean exhaust pipe

Step 2: Fuel pump

Check delivery quantity of fuel pump

Possible defect Remedy
Excessive fuel Correctly adjust delivery quantity

Step 3: Combustion air intake

Check combustion air intake for free passage (visual check).

Possible defect Remedy
Intake blocked Clean combustion air intake

Step 4: Combustion air blower motor

Check combustion air blower motor speed.

Possible defect Remedy
Battery voltage too low Charge battery
Blower fan loose (chafes) Remove combustion air blower, secure blower fan (note air gap of .039”/1 mm) and install new blower fan if necessary
Speed is not attained at nominal voltage (6400-7100 rpm) Remove motor and check, install new one if necessary