Most “popular” mistakes people shouldn’t make around the house electric panels:
Relocating water heater or furnace? – don’t run any of the pipes in front of the house’s electrical panel – remember 36” distance from its face must be free of any obstructions.
Painting the wall? – don’t seal the electrical panel door with silicon or caulking; and don’t paint the breakers or panel interior (when spraying paint for example).
Building any frames / walls / cabinets / doors around the panel? – make sure that the front cover is easily accessible and removable. The cover might need to be unscrewed for servicing and sometimes, the opening left around it is not big enough to access circuit breakers / fuses. Also, always keep a 30”x36” clearances when building any enclosures.
Don’t place paneling, drywall, or any other wall finish materials between the cover and the electrical panel enclosure – it will separate them and raise the cover, creating gaps around the breakers (some electrical panel covers may have an adjustable depth section).
Screws securing the electrical panel cover must have a flat tip (any hardware or an electrical supply store will have them); don’t use any drywall type screws or any other sharp point screws because they might damage wire insulation inside the enclosure, short a hot wire, or even cause a fire. Removing the cover should be done by a professional, but you can replace each screw individually without even removing the cover. Before doing it, check the cover for any overheating marks, burns, and use insulated screwdriver. If in any doubt, ask a professional to do it for you.
Do you have a legible description of all circuits inside the electrical panel? – It is required. Before testing all the breakers, turn off electronic equipment and disconnect any sensitive appliances, like the refrigerator. If you don’t have a electrical outlet tester, you can get one in every outlet store (they’re very cheap), or use a table lamp – it won’t tell you if it is wired properly but you can at least mark the breaker.
Is your electrical panel missing any breakers? – all openings should have special plugs installed (electrical supply store will have them, just tell them the panel brand) – notice on the picture that high voltage bars inside the panel are exposed. Especially if you have small children running around your house – take care of it!
Are there any holes (missing knockouts) in the sidewalls of the electrical panel enclosure? There should be special plugs installed to seal all the holes and prevent possibility of a fire spreading out of the electrical panel enclosure (any hardware store, measure the diameter).