How would the plumber test for scaling, do they cut the pipes open to check? I read about pouring vinegar into the hot water tank to descale.
For poly-b problems, I have read about these options:
1) replace all polyb pipes
2) add a heat exchanger, a backflow preventer, and add chemicals (?) to system
3) use only non-rusting components: boiler, expansion tank, air scoop, pump, pipes
4) add "water treatment" and test it often (is that the same as "adding chemicals"?)
Which option would you guys recommend? I understand that replacing the pipes may become necessary -- how much roughly should it cost to re-pipe with say PEX for a 4000 sqft 2-floor house for radiant floor heating?