Suburban furnaces are serviced out side by removing 4 screws on the panel. Panel will then pull out with intake & exhaust tubes attached. Turn off propane. Disconnect propane line Remove 1 screw in the center below the motor to pull the unit out of its cabinet partway to access curcuit board on the left side. likely 4 wires going into the rig, blue and green to thermostat- check continuity to thermostat to verify its working!
red and white are power and ground.
If you are sure there is 12v to the board, thermostat calling for power, then check 12v to the motor and gas valve. Then --- still no go?
Mark which wires go where, disconnect the nuts, take the unit to a dealer to bench test the board.
A new dinosaur board is about $100, much better, has operation led lights.
Did my '09 carriage furnace last month Hi voltage transformer would not spark. fan ran, gas valve opened-- you can hear feel and smell that--- , no spark to light.
All it takes is a screwdriver, multimeter, a wrench.
If there is power and the thermo. is working, the problem is in the unit.
