This might happen due to corrosion to the orifice and you don t have any choice apart from replacing it with a new one.
Propane wall mount heater shuts of after 30 sec.
If heater keeps shutting off see troubleshooting pages 22 through 25.
If heater shuts off do not relight until you have provided fresh outside air.
Keep all air openings in front top and bottom of heater free of objects and debris to ensure adequate air for proper combustion.
If you re sure the unit has gas clean the aperture of the gas valve with a needle.
Another reason of such blockage is the presence of air in the gas line.
On wall mount heaters it is usually located on the front of the heater near the floor.
If heater keeps shutting off have it serviced.
Gas valve are allowed 30seconds to fall out.
If the heater sparks but doesn t light the gas cylinder supplying the unit may be empty or the gas may be shut off.
Turn the control from the on position all the way over to the off position.
The third reason of why your propane heater keeps shutting off can be a blocked up gas valve orifice.
There could a fault in the gas valve s main burner solenoid causing it to draw excessive power and starving the pilot flame solenoid.
How to troubleshoot gas wall heaters.
Step 2 close the empty propane tank if it is small enough to remove by turning the handle counterclockwise as far as it will go.