Natural Gas wall heater. I have a natural gas wall heater, 65"high and 16" wide, it runs for about

Question

I have a natural gas wall heater, 65"high and 16" wide, it runs for about 10 minutes and shuts off.?? can you help, Thank You>..

I have a 30,000 btu Glo warm wall pack (13 years old ) the pilot lite will not stay lit one the system cycle . if i clean it it will work for a few days then strt to go out .any idea's on how to fit it .i have changed the thermocoupler last year helped for a week .