Had a hvac company come to fix my vanguard gas wall heater. Problem the pilot light would not stay lit. They said all it needed was cleaning. They said they cleaned it and I thought they had fixed the problem; until the same evening approx 6.2 hrs after they left the pilot light went out again. Sometimes it will stay lit for 10 minutes sometimes for a few hrs but continues to go out. I was unable to get another hvac company out yesterday and today it's a chilly thanksgiving day in Oklahoma would greatly appreciate any suggestions. God bless and thank you to anyone that comes across this post.

Look at the pilot & how well it envelopes the thermocouple. The pilot should cover aprox. the top 1/3 & wrap around the thermocouple. If it does not, the pilot may need adjustment.