No warm air flow

Step 1: Warm air duct

Check warm air duct from heater to body for tightness

Possible defect Remedy
Clamps loose or hoses dropped down or damaged Secure loose parts, replace damaged parts with new ones

Step 2: Fuel delivery

Loosen hose clamp, disconnect hose to heater briefly (2 secs) at fuel pump, then check whether fuel is delivered by pump. Catch escaping fuel in a cloth.

Possible defect Remedy
Check fuel supply Fill fuel tank
Fuel filter blocked Install new fuel filter
Strainer dirty Clean strainer
Fuel check valve blocked Replace fuel check valve and readjust delivery capacity

Step 3: Glow-spark plug

Switch heater off. Remove glow-spark plug and check

Possible defect Remedy
Thermo switch defective (no current, glow time too short) Install new thermo switch
Glow element open Install new glow-spark plug
Glow-spark plug dirty Clean glow-spark plug
Ignition contact breaker defective or maladjusted Adjust contact breaker or replace if necessary
Ignition cable or coil defective Test ignition system and install new parts if necessary