Hi Kelly, Is water quality an issue in that location?
More than one tankless manufacturer lists max levels of all or some of the following: pH - 6.5 - 8.5 TDS (Total Disolved Solids) - 500 ppm Total hardness - 6 grains Aluminium - 2.0 ppm Chlorides -250 ppm Copper - 10 ppm Iron - 0.3 ppm Manganese - 0.05 ppm Zinc - 0.5 ppm as qualifying for the addition of a water conditioner or softener. In my experience, many folks, even with conditioning/softening equipment installed (oftentimes inop), are blissfully ignorant of the effects of water quality until something stops the hot water. I personally like Bob-O's approach of a warning label at the hot faucet for solar applications. The code officials in my neck of the woods do not share my enthusiasm for this approach. Because here in STL, we additionally have a chloramine presence in the water this adds a requirement for specialty o-rings, etc. for control items in the water path. Hope this helps, Bill Loesch Solar 1 - Saint Louis Solar ----- Original Message ----- From: "Kelly Keilwitz, Whidbey Sun & Wind" <ke...@whidbeysunwind.com> To: "RE Wrenches listserve" <re-wrenches@lists.re-wrenches.org> Sent: Wednesday, May 19, 2010 1:14 AM Subject: [RE-wrenches] SWH - mixing valves > Thermal wrenches, > I'm having an ongoing issue with mixing valves in my own system not > keeping a steady mix domestic HW temperature as the tank temperature > varies with solar heating. If I set it for (say) 122˚F mix when the > tank is 135˚, it seems to hold that differential at all tank temps - > i.e. when the tank is hotter the mix is too hot (sometimes dangerously > so), and when colder the mix is too cold for a comfortable shower. > Thus, I need to change the setting all the time. > > I'm now using a Honeywell valve with a 90˚ - 145˚ range. This is a > replacement for a valve with a wider range that acted the same way. > Any ideas, suggestions for better valves, or....? > > This has me wondering how many of our SWH customers are experiencing a > similar thing, but just aren't bothered enough to say anything. We > seem to have encountered many plumbing situations where the mixing > valve allowed weird backflow or siphoning situations to mess with > system operation, especially with HW recirculation. I thought I had > all such causes eliminated on my system, but maybe not. > > Thanks for sharing your experience with such matters. > -Kelly > > Kelly Keilwitz, P.E. > Whidbey Sun & Wind > Renewable Energy Systems > ke...@whidbeysunwind.com > 360-678-7131 > > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
