You need to make sure you have the cut off valves. I moved into a house and the previous owner had put the tankless in without there.
Use a sump pump in the bucket to create a circular flow of water from the bucket, through the heater, and back into the bucket. Run that for 45 minutes.
cena05
11:41a, 4/18/24
In reply to HalifaxAg
Do you have a water softener?, if so you can space out the descaling considerably.
Whitetail
12:40p, 4/19/24
I use one of the descale flush products for this on Amazon. It's like $20. In use a bucket, hoses, and a pump as described to flush. Pretty easy. My water is not softened and has minerals so it is part of my yearly home maintenance plan.
kyledr04
6:01p, 4/20/24
Only difference is I use a drill pump and whoever installed the valves did it so that the drain side is turned sideways so I have to use a flexible hose and clamp