Spluttering cozy cabin heater (gas)

[armchairsailor]

I installed a second hand propane cozy cabin heater a while back. It works well but after some time, say, 20 minutes, it begins to splutter and roar. After a few minutes of this the flame starts to misbehave and I turn it off for safety’s sake. I have put it down to the burner unit warming up and disrupting the flame.
I’m loath to adjust it as it’s a potential fire risk, but has anyone encountered anything like this before and found a fix?
It’s an old unit that I managed to find a new burner cap for, as that was the only thing missing. I’ve made no changes to it past that.

 

[thegasmannick]

sounds to me like you need to get specialised to look at this and not attempt yourself
without going into detail`s id say it flame lift off with either flue or vitiated air if its either its lethal so dont attempt any repair`s id say replace or repair (gas safe engineer only) and i hope you have a good carbon monoxide detector if not you might be lucky to be still here