Heater is smoking and doesn't start after several attempts

This is a usually a fuel-related issue. To diagnose, carry out the following steps:

• Check fuel quantity output of the heater according to the repair manual.
• If the amount of fuel is insufficient, check the standpipe, fuel lines and connections.
• Check the fuel filter and fuel pump. Replace the filter or pump if necessary. 
• Check the glow pin and replace the glow pin screen if necessary.