Primary Secondary piping

James Day_2

Hey guys. I have a question about primary secondary piping for boilers utilizing both low temp apps. and high temp. When you do your primary loop off the boiler, Should you use crossover bridges to feed all of your secondary circuits. Or can you using closely spaced tees header your branches like your were piping an average boiler and just add 3 way valves for radiant zone.  Any thoughts would help.

meplumber

I use closely spaced tees or hydronic separators.

When I am primary/secondary piping, I either use closely spaced tees or a hydronic separator.  Then I pipe the supply and return as normal.  For the radiant zones, I use mixing valves.  For the high temp (hydro air or fin tube), I let it fly.



I have also found that the regular, old thermostatic mixing valves work great.  No need to overcomplicate with the outdoor reset valves.  If your boiler has outdoor reset, then you are just repeating the process.  Plus when the mixing valve starts acting up on a Saturday night, I keep a Honeywell AM series in the van.  It is an easier swap out.