1 - May have to remove existing connections, clean and redo. I have seen crooked cuts and little cracks at the ends of the lines come loose from travel.
2 - The guy who wired my stereo was not an electronics installer, probably the guy who tightens lug nuts on the mfr. line. After fixing that it's easy to replace with a different car/marine stereo.
3 - Check power at unit, sometimes the fuse holders come loose inside and they look fine but power is not getting to the unit. Otherwise some models are servicable and some are not.
4 - As long as it's a heater designed for the application it just means cutting a hole in the wall(!!) and extending a propane line. I've seen some real simple to install wall units. My personal opinion is that I would not use anything that introduces flame inside the unit, even if they say they are safe.
5 - Happens to me frequently, it's the water/steam being created by cooking. It's possible that the window may not sealed anymore, after 7 years even house windows can leak. If it's between the panes on a double pane window then the seal is broken.
