Plumbing in the Home/Rinnai Boiler
Peter Roan wrote at 2013-02-13 04:07:05
Bla bla bla... If you can't help then shut up. Licensed technician? What the hell does that mean? Are you trying to say licensed plumber? Get a life. I can't stand generic bullshit answers from people who have no idea what they're talking about. If you know the trade and don't want to help then shut up and move on.
Anyway, concerning your question regarding the circulator pump; the on board Grundfos pump is there because the boiler has two separate heated water loops. The main loop which is the heating loop gets pushed by the on board Grundfos pump through the stainless steel block and to the heating system. Whenever there's a demand for hot water, the potable water gets heated through the stacked plates that's shared by both loops. Since the main loop shares half of the plates, the potable water passes through the remaining plates by pressure and catches the heat from the other plates. This way the potable water never mixes with the boiler water. You still need a separate pump for each zone for your heat whether it's for your high temp or low temp heating. Get your hands on the installation manual online; there you'll find several diagrams with parts recommended to install the combi boiler.
Regarding your other question you need a limestone neutralizer because of the acidity of the condensate water. Make sure to use a condensate pump if your boiler is not next to a drain.
Good luck and be safe. You can do it if you follow all the installation recommendations and if you take your time with each step of the installation.