So i have been reading here for a while and decided to make a post with some of my thoughts on boiler replacment. Getting rid of a oil boiler with a junk tankless coil (big suprise). I have really been thinking about the Embassy Onex Combi but im afraid it will not modulate down low enough (goes down to 30K) (http://www.houseneeds.com/shop/mestek/embassy-ambassador-onex-ox-160c-buy.asp) But it does have a hot water coil. So i would use my 2 year old 80 gallon electric water heater as a buffer tank and pump 140 water into it and use a temp valve to lower the output to 130. giving me lots of hot water. Cost is also high for this unit and it uses it's own special venting. The other choice is to use a solo 110 76000 btu or a viessmann wb1b 87000 btu and build a fresh water loop into my electric hot water tank with a plate heat exchanger and loop the boiler to the other side of the exchanger. I think the TT Solo lends it self better to DIY installs along with the Onex. But most people speak highly of the viesmann. So there are my thoughts.. Some detail about the house. 6 year old garrison @ 1200 Sq ft. 2 heating loops and adding a third for a total of 63000 or radiation at 180 water temp. still trying to figure out my heat loss calc. I think it is 35000 at -2 but still learning. House is in central NH with 8000 heating degree days. I have my Head loss numbers for my loops and have sized what pumps i should use. Just still stuck on this hot water issue and the best way to go about it. Thanks for viewing and sorry for the long winded post..