What is the background on the problem? Is this an intermittant problem? Is the stove making any unusual noises? Is it clean? If I understand you properly, you start the stove, it runs for 30min then shuts down? The stove has a 12-15 min start up cycle. During this phase, the pellets feed normally and everything works. During this strtup cycle, the stove should heat to a pre determind temp and trip a sensor that tells the circuit board that it is ok to continue operation after the start up cycle is completed. If the stove fails to heat to the temp, or if the sensor is bad, the stove will go into a shut down sequence. It will stop feeding pellets and shut down. This may take up to a 1/2 hour to complete. This will give an "L" message. If the auger motor has failed, the stove will not even get to this point because it will have never fed any pellets to start the stove in the first place, so I doubt this is your problem.
The "E" message on this model can be from a few different sources, like if the vacuum switch fails, or if the auger motor suddenly fails during operation, if the auger gets jammed, ect, ect. To check the auger motor, plug direct power to the auger motor, you should see the motor running continuosly. also, put a multimeter on the leads to the auger motor and check for voltage while the stove is in operation. You should see voltage coming thru the leads in bursts of 1-3 seconds. My guess is that you will not see power coming thru after the start up time has expired, so at this point you will check the vacuum switch. The vac switch is the round disc like object attached to the back wall on the left side of the stove. It has a rubber tube attached to it. Disconnect the leads from it and connect the leads together. If the stove runs, disconnect the rubber hose from the vac switch and blow it out. Sometimes ash plugs up that hose and prevents the switch from operating properly. Hook up the wires to the vac switch and run the stove again. If it still doesn't work, replace the switch. If not already done, clean out the exhaust blower and venting.
Make sure that you re- attach the rubber hose to the correct nipple or it will not work when reassembling. Do not run the stove for any more time than necessary to do your testing with the vac switch bypassed- it is an important safety feature.
Good luck.