On another matter, the I/O manual states that it and another heating appliance can be tied to the same flue with the proper saftey controls and references a NFP code to do it on page 5. Anyone care to comment on that one?
Most likely the reference in the New York Boiler installation manual that suggests chimney sharing with more than appliance is out of date. In fact the referenced section 5-8.2 no longer exists in current NFPA 211 edition. It may have be true years ago but it is definitely not "code" today. The National Fire Protection Association (NFPA) publishes safety standards for many things related to fire. NFPA 211, Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, is the one that applies to our coal burning appliances. The latest version of NFPA 211 is available for reading on their web site. http://www.nfpa.org/codes-and-standards ... DocNum=211
Scroll down the page to where it says, "View the 2006 edition of this document". This link will take you to where you can read but not save, print or download the document. No where in NFPA 211 does it say you can or can not share chimney flues. BUT NFPA is not a regulating agency, it's a standards agency.
What you can do and meet "code" where you live is regulated by your state and local governments. Usually there is a state wide minimum "code" that becomes state law. This law, also usually gives local governments the right to enact tougher regulations. Enforcement is almost always at the local level. State and local governments are not qualified to create the code standards so they usually adopt some existing standard that's created by a standards agency. For example the Underwriters Laboratories (UL) we are all familiar with. For building and construction codes the "International Code Council" (ICC) is often used. The ICC's International Mechanical Code is what applies to chimneys. I own the 2006 edition of this code. Here's a quote from Chapter 8,"Chimney and Vents", "Section 801.11 Multiple solid fuel prohibited. A solid fuel-burning appliance or fireplace shall not connect to a chimney passageway venting another appliance."
IT'S CLEAR YOU CAN NOT SHARE CHIMNEYS.
The version of the ICC Mechanical Code I own is the non-location specific code. It is always possible that what applies to your local community is different. Check with you local government building code enforcement officials to learn what applies to you. You can read some ICC codes on line. For example you can read the New Jersey Mechanical Code on line at: http://www2.iccsafe.org/states/newjerse ... ameset.htm
Again you will not be able to download, print or save. The Chapter 8 section of the NJ Code is identical to what's in my paper code book.
Sometimes adopting state wide codes have unintended consequences. Pennsylvania adopted the Pennsylvania Construction Code Act on November 10, 1999 which made all residential coal fired boilers without code stamps illegal. It was illegal because the ICC code they referenced said residential coal boilers need code stamps. It took a amendment, Senate Bill 1179 Session of 2006, to correct the problem. Rest easy all you Pennsylvania coal burners, you are now legal.