The knobs, burner coils, burner sockets and gas tubes are some parts of a gas range that a consumer can replace. Other self-replaceable parts include drip trays, grills and the rotisserie.
Knobs tend to wear out with heavy usage or rough handling. To replace them, simply pull them from the range with dry hands or use pliers and lubricants if they are stuck in place. Once pulled out, the replacement knobs must be pushed to the internal shafts for correct alignment. Universal gas range knobs are good replacements for most gas range brands.
Burner coils tend to char or get burned. They also fail to light, in some cases. The primary solution is to switch the bad burner with a good one to check if the problem lies with the burner or with the burner socket. If the good burner works, it is a burner issue and a replacement burner coil is the solution. If the good burner does not work, the problem has to do with the burner socket. This can be solved by unscrewing the socket from the gas range and replacing it with a new burner socket.
Gas tubes crack with age. The gas valve must be closed first, the faulty tube unscrewed from the range and the new tube screwed into place. As a precautionary measure, it is good to unplug the gas range from the power connection before any replacement is done.