In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Navien "Mod-Con" Turn down
First off, I am NOT a fan of Navien, or any of the wanna be tankless models trying to become condensing boilers. But that's just me, don't let my bias interfere with your opinion. However Navien apparently has their new CH series with is a combi series aimed at doing both hydronic heating and domestic hot water all in one. According to Navien they are listed with an ASME H-stamp, AND they have 3 models with turn downs from 10 or 9 to 1 or in that range (17,000 to 150,000, 20,000 to 175,000, and 20,000 to 199,000).
So they are essentially certified with an H-stamp with these turn downs, yet no one else can get these turn down ratios? Is there another standard more common mod-cons (e.g. Lochinvar, Viessmann) must certify to that we don't know about, or another set of rules to get higher turn downs?
Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber