Mark,
How often does
Butler say to run before you descale?
Do you just look for scale or a loss of heat/flow?
The Clean Machine
Would have to look at the manual as to how they word it, but it is pretty general depending on water hardness in your area.
We descale about once a month, but just down the road about 60 miles my brothers have way better water and don't have to descale very often.
I plugged up here a couple years ago, and find that the higher heat units build up more scale quicker, so actually it is the end of the month and we will descale soon.
It is also time for us to dump all fluids in the cat pump and blowers. We do it way earlier than recommended....just what we do.