Steps to Start the Furnace (General):
1. Propane Supply: Ensure you have a sufficient supply of propane in your tank. Check the gauge on the tank.
2. Thermostat: Set the thermostat to a temperature higher than the current ambient temperature inside the van. This signals the furnace to activate.
3. Fan Switch: Many Suburban furnaces have a separate fan switch. This may need to be turned "ON" (or to "AUTO" depending on the model). This circulates air, even if the furnace isn't actively heating.
4. Ignition: The furnace should automatically ignite. You'll likely hear a clicking sound from the igniter and then the whoosh of the burner lighting. If it doesn't light after a few attempts, stop and check for gas leaks before trying again.
5. Ventilation: Ensure adequate ventilation inside the van. Carbon monoxide is a deadly byproduct of incomplete combustion. Never run the furnace in an enclosed space without proper ventilation.
Troubleshooting if the Furnace Doesn't Start:
* Low Propane: Check your propane tank level.
* Thermostat Issues: Check the thermostat's batteries (if applicable) and ensure it's set correctly and functioning properly.
* Pilot Light (if applicable): Some older systems have a pilot light that needs to be lit manually. Your owner's manual will explain this.
* Gas Supply Lines: Check for any kinks or obstructions in the propane lines leading to the furnace.
* Fuse or Circuit Breaker: Check your van's fuse box or circuit breaker panel for any blown fuses or tripped breakers related to the furnace.
* Safety Switches: Some systems have safety switches that can prevent the furnace from starting if something is amiss (like a door being ajar).
Warning: Propane is highly flammable and potentially explosive. If you smell gas, immediately ventilate the area and do not attempt to light the furnace. Call a qualified RV or appliance technician to inspect the system.
This is a general guide. The specific steps and locations of components will vary depending on the exact model of your 1979 GMC Vandura furnace. Locate your owner's manual – it's essential for safe and proper operation. If you can't find it, you might be able to find a copy online by searching for the make and model of your furnace (often found on a label on the unit itself). If you're still having trouble, it's always best to consult a qualified technician.
