Is it a catalytic style of heater? If so, is it vented or non-vented. Non vented is what is in my 1981 and while it is like new and operates as such, I do not use it unless there are windows or vents open. They don't use a lot of propane compared to forced air styles I have had but can be dangerous, to the point of wake no more. If it is vented they are much safer but less efficient. I have added an Espar diesel heater for my main heat source and have found it better all around than propane for my needs.