Just had this furnace installed and the furnace would only stay running with the cover off on one side. I did have to move a wall so I though maybe the issue was over heating. The wall is now moved but the same issue occurs. If I put the cover on the furnace shuts down after about a minute of running and I have to hit the reset button to start it up. This is the Williams double sided gravity wall furnace. Flame is blue when the furnace is running.

SOURCE: Williams gravity vented wall furnance - where is the pilot?

Its in the bottom of the heater behind the vent cover . I don't know where you are but your local gas utility will come out and lite this for free.

SOURCE: furnace is not staying lit

if the main burners are firing but goright out it could be the flame sensor which is a straight wire with one wire going to it you can clean it with steel wire or fine sand paper if not check the flashing code on the control board

SOURCE: Pilot adjustment on Williams wall heater

The insert sounds like the cap covering the adjustment screw. Pin hole is for cap removal. Wondering why flame is so high?! Shouldn't have orange flame. If heater doesn't light with lower flame... thermocouple (thing that the flame heats up) may be bad.

SOURCE: Amana Furnace runs shuts down then relights

flame rod sensor

SOURCE: FURNACE COMES ON AND SHUTS DOWN WITHIN 15 SECONDS

On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control). When all else fails, check the ground connection for corrosion.