so water with Ca and Mg in it, how does it negatively affect these?
Hard water doesn't effect plastic plumbing, but could create mineral buildup in metallic conduit. Same thing on the boiler, since it's metal.
Chemistry answer hard water means water with a relative high concentration of carbonates, Ca2+ and Mg2+. 2 HCO3? ? H2CO3 + CO32?. H2CO3 ?H2O + CO2. CO32? + Ca2+ ? CaCO3(s) Summarized 2 HCO3? (aq) + Ca2+ (aq) ? H2O(l) + CO2 (g) + CaCO3 (s) When heating water, CO2 evades(?) quicker, thus the equibilriums move to the right, causing a pile of CaCO3 inside the pipes/boilers, ruining the heatflow.
Well if you have a heat exchanger that is using hard water steam to exchange heat, then you will encounter what is called fouling in the equipment. This means that you will slowly start to have buildup and then the buildup is non-removable. Thus, the equipment has been ruined. The heat transfer area would be compromised, and you would have a faulty heat exchanger. In your terms, heat exchangers are series of pipes, either concentric or cross flow. Water flows in one pipe adjacent to the concentric one. When this happens, one has a hot fluid the other has a cold fluid, and there is heat transfer. When you have hard water, there is a 99% chance that there will be buildup of the minerals present inside the pipe during heat transfer. This will cause blockage in the pipes and will cause you to spend a bunch of money replacing the pipes.
