The first inequality means that the distance between x and c is greater than 0 and that x â  c, while the second indicates that x is within distance Î´ of c. Note that the above definition of a limit is true even if f(c) â  L. Indeed, the function f need not even be defined at c.
Once inside a hot water heater, however, Legionella bacteria multiplies and is conveyed through the household plumbing, where it may be inhaled in the aerosol mist that accompanies showering, bathing or even washing dishes in a sink. Very young children and elderly people are particularly at risk.
Depending on hot-water usage, preventive maintenance and the amount of water impurities, the life expectancy of water heaters is 10 to 15 years. Thatâs approximately 3,650 to 5,475 days in a row the water-heating system is âonâ â heating, reheating and storing hot water. With this kind of work schedule, itâs plain to see why maintenance is so important. Trouble signs: Leaky water heater.