I had a tankless water heater installed with isolation valves. The setup that I got is a little different from what I normally see, and I'd like to make sure that this is a good solution and I'd like to ask a few questions about descaling with this setup. There are two shutoff valves, one each on hot and cold lines. However, there are no drain valves on these valves, all they do is shutoff water with no way to attach lines for descaling. Instead, flexible hose is used to attach from these lines to the tankless heater. Here is an image of the attachments from the lines to the hose:
The hose is marked as stainless steel water heater hose, 3/4" FIP.
My questions are:
Is this setup an ok installation?
To descale with this setup, I assume that I just close the valves, unscrew the hose, and re-attach it to a pump to run descaling solution through. Is this so? Is it better to unscrew the hose at its attachment to the lines or at its attachment to the heater? When I re-attach the hose, should I put anything on the threads such as pipe dope? Will there be any problem long term with repeatedly unscrewing and rescrewing the hose every time I descale it?