The 4000 series which includes a smaller 2000 model and a 5500 Turbo!! which in fact is identical to the 4000A was the new generation Carver fire introduced for the 98 season. Most being fitted with a new type electric blown air heating, they are now commonly known as the Fanmaster mk2. This type have separate electric heating elements which can be used for background heating at night without the noise of the fan running.
They work very well and provide excellent heating but are now suffering from a distinct lack of spare parts due to their new owners total lack of support.
There are two 4000 models, the 4000 with manual 'piezo' ignition and the 4000A with Automatic electronic ignition. To light the gas you must press down momentarily release and turn the control knob to the 'zig-zag' mark on the fire top. The spark if an automatic ignition model will have already started providing the 12v supply to the heater is switched on and you can check this with the Fanmaster slider switch control lights also on the fire top if this is fitted.
The control knob has to fall into a slot for the fire to light, what I find easiest is to start to turn and then press down again, as the knob then reaches the slot the knob will fall that little bit further into the slot and lock. Again if Auto it will now light, continue to hold down for 10-20 seconds to allow the thermocouple to warm up and then release. This is pilot light position and to light the main burner another momentary push and turn will move to minimum, continuing the turn toward maximum will light the main burner dependent on temperature.
For the manual model follow the above but once in the slot repeatedly release and press down fully to work the spark and light the burner. As the manual takes a little getting used to, I think it wise first to practice with the gas off so no problems occur when lighting for real!!.
Hope thats understandable as far as it goes but if it does not light assuming you have gas to it, then there are several faults which can stop it lighting.