[TedfromGA]

In Atlanta Ga. we had Tankless water heater. The water in the Atlanta area had much less disolved calcium than water here in The Villages. I used CLR (Calcium Lime Rust) which you can get at Lowes/Home Depot/Ace. I descaled once a quarter. Why? Our tankless was a $3,000 investment and in each descaling cycle there was enough calcium to be noticable.

Here in the Villages the desolved calicum is very high. A water filter will NOT remove the calicum. A water softner will. So if you don't have a water softner you need to descale once a month and with CLR, not vineger. The calicum build up inside the heating coils of the tankless will adversley effect the efficiency of the unitl and eventually you'll have to replace the unit.

FYI - to see the effect of calicum take a teakettle or pot, fill it with 2 cups of water then boil it dry. If you see white residue (calicum) you have a problem with tankless systems and need to descale often.

All you need to do the descaling is: 1) a 5 gallon bucket; 2) 2 short hoses; 3) a pump ( I used a small circulating pump from Amazon; and 4) 1 gallon of CLR. Put the CLR in the bucket and fill with water. Run this for 30 minutes (or when the solution in the tank stops foaming) and then flush the tankless with water for 5 minutes once a month.