All combustion type furnaces require combustion air, depending on age of house, local codes etc. Sometimes surrounding air is adequate, sometimes you require "make-up" air, which is why you have that kit available. The experts here will tell you more, presumably, if your boiler was installed professionally, you have what you need. The main thing is to ensure that there's enough air entering through leakage or intended vents, so that products of combustion - CO2, CO etc are not being sucked back into the house from the furnace/boiler etc. In newer houses which are quite airtight in comparison to older ones (or should be) this is very important for safety. In some you will see a metal duct that leads from the outside to the furnace room, with a cage over the end, this provides combustion air.

I have a boiler system in my 1960 2 bedroom ranch. I love the way it warms the house, but my only problems/complaints are: 1.) When the heat starts up you can hear the copper fins "clicking" as the expand. This is because the previous owners have them all banged up and at some point I'll have to straighten them all up. 2.) You'll need a humidifier. My house gets extremely dry during winter months and we had to buy several small units and put them in the bedrooms. I wish i had a whole house unit to add humidity, but there is no way to do this using a hyrdonic system.

Let me tell you about "junk" LIner mfg'rs recommending stainless with coal - 2-5 year lifespan w/ sudden complete collapse causing a potentially life-threatening situation. This is typically 316L or ti, the most corrosion resistant stainless liner material. Complete collapse - looked like a slinky. Lining was recommended strongly by installer - tile liner was in excellent shape and this potentially deadly disaster could have been completely avoided if the chimney was never lined with stainless. Liner mfg'r did step up and offer a free replacement. (North east Penn); Stainless class a metal stack interior collapse after three years w/ coal ( Coal rated and warrantied chimney - documented - Fredonia, NY) + Many more. Stainless class a chimney failure 316L (Westport, NY) Less than 15 years use w/ well maintained oil boiler. Top two sections failed internally from corrosion - every section had visible pin-holes. Stainless 304 liner failure - top three sections badly pinholed/pitted and many remaining parts felt like aluminum foil (Akron, NY) Numerous aluminum liner failures including total collapse w/ Nat. gas (Buffalo, NY) Partly due to poor installation practice (uninsulated liner in unlined masonry flues in contact with alkaline mortar parging and joints). Many other liner failures were partial failures of the liners (either top or bottom) and could not be attributed to faulty installation. One of the few areas where stainless liners DO serve the purpose of increasing safety is in flues serviced by enclosed wood-burning appliances - stoves, boilers, and furnaces. With wood, there doesn't seem to be widespread pitting corrosion the stainless steel (hopefully insulated) offers protection to any masonry against the rapid temperature rise and damage of a chimney fire. Chimney fires, of course, are a non-issue with other fuels. With fuels other than wood, a metal chimney liner is often not necessary and CAN fail catastrophically - potentially causing an unsafe condition that otherwise would not exist. This is especially true with fuels such as coal and heating oil.

I had a plumber install a Rinnai E110C in my house(built in 1915,I live in Massachusetts) in September of 2014. So far I am very happy with it. The time it takes to get water my shower upstairs(about a 30 foot run from the boiler) is about 10 seconds in the summer and maybe 15 seconds in the winter. Ground water temp in my area is about 52 degrees. However there were a few issues that I experienced. First, I had a concentric intake/exhaust pipe installed out the side of the house. When it would rain, water(the rain) would get into the intake portion of the tube(the outer pipe) and make its way back into the boiler casing and splash around and condense at the bottom of the unit. This is something you don't want to happen as the electronics are housed here. The pipe outside the house was positioned in the corner of where two porches on the house meet and when we would have a rainstorm this was a turbulent side of the house. I eventually had the plumber reroute the intake/exhaust to a two pipe(separate pipes and at an added cost of $800.00 to me) system and on a flat wall in a different direction. Problem solved. My Rinnai E110C is positioned where the oil tank was. I had put speedi dry down where the tank was and right under the two pipes for hot water heating and return at various times There were moisture spots about 5 or 6 inches in diameter. Putting my hand on the pipes leading into the low loss header, my hand was wet with moisture - condensation. The low loss header itself is insulated with stiff Styrofoam. Just today I put insulation on those pipes and hopefully that will solve the problem.