Thanks. I'm thinking my best bet right now is to do nothing as well and see what develops. Our boiler is only 4 years old and in great shape. Also, this may be interesting should it pan out and depending on the cost: http://www.geappliances.com/products/water/heat-pump-water-heater/ I looked up the Stiebel Eltron unit - it retails for $4,500 and I saw $2,799 as the best price, and only has a 5 year warranty. At that price, even if it cut my DHW costs by 75% (which is doubtful - 50% is more realistic) it would still be a 4-5 year payback to just break even.