Upgrade to high-efficiency condensing boiler/water heater

LongIslander

I am in the middle of a renovation and considering upgrading my gas systems.  The boiler is an original Hydrotherm 144,000 BTU and the water heater is a Bradford White 48 gal 65,000 BTU unit about 15 years old.  It is a baseboard water fed system with three zones.  I'd am in the middle of an exterior renovation and would like to knock my chimney down since it is in a bad spot and not cosmetically attractive and convert to a direct vent condensing system but the pricing is all over the map ($9.5K to $14K) and every estimate recommends different gear, some with separate water tanks, some with separate instant hot water systems. 

My house is about 3,000 sf on Long Island NY and my annual bill is about $2,800. Is it really worth it to do the upgrade (and what will the payback be) or should I just replace my water heater, box out my existing chimney to match the new exterior and call it a day? 

Robert O'Brien

Based on real world experience

You should be able to slice that in half with a  mod/con and indirect or tankless water heater. This job is in Manhasset