I live in a condo where all get hot water from same source. We have been told we need to descale our pipes with a chemical process that is very costly. does it work?

If it's acid they want to put iunto your pipes be aware that it might damage the pipes and if it's some "gee-whiz" electromagnetic gadget that attaches on your pipes check it out very carefully. What are they trying to sell you? Let me know and I'll check it out for you. Regards, Tom