Heating appliance venting systems website needed

I’m looking to link to an easy-to-navigate site with clear, simple examples of venting configurations, especially showing direct vents and sealed combustion.

If you got to burnham.com That company makes direct vent oil fied boilers,also wiel-Mclean,Utica and others. If you go on there sites check the instalation sections and you will get plenty of info. Hope this helps.
Regards Len

Thanks Leanard, this is for a reference source, so I’m trying to stay away from company sites, hoping to find industry or non-profit sites, preferably not PDF’s cause, man, I got a ton of these things to install and PDFs take so long to load and are so specific.

Sound kinda’ picky don’t I :wink: .

If you have a bunch of them to install they must have instructions with the units??? If not the vent kits will have them.
Len Ungar CMI


Try this;




Almost everything is in PDF.

Marcel :slight_smile: :slight_smile:


In my area, there have been two generations of “sidewall” exhaust systems for oil heating equipment:

(1) In the 1992-2002 period, the furnace or boiler was still the older loose ungasketed style that depended on negative natural draft to aspirate the system combustion gases. In this period, an approved exterior wall amounted exhaust fan was connected to the appliance flue…it essentially replaced the chimney. It was wired/timed to initiate a pre-flame purge cycle to set up good air currents through the unit and there was a 3-5 minute post flame purge cycle to fully exhaust combustion gases.

(2) From 1997-8 to present, the sealed system “direct vent” or “balanced flue” systems have taken over. The appliances are now totally sealed and the oil burner fan actually serves to create the proper conditions for combustion as well as draw in outside combustion air and exhaust the combustion gases. These systems have to be 100% sealed on the positive pressure side of the burner and fire chamber or you’ll have the escape of exhaust gases into the house.

In Canada, there is a nationally recognized-by-code Canadian Standards Association document (CSA B-139: Installation Code for Oil Burning Equipment) that sets the requirements for the location of the exterior exhaust on buildings. It’s similar to what you would’ve found at the Burnham site. Our distances for certain clearances are more stringent though.

So… yes, direct vent systems will work with oil-fired appliances as long as they’re equipped with the necessary fan. Right?

In instance #1, you had to have an exterior wall mounted fan. In #2, the oil burner blower/fan itself does the job…no exterior fan needed.

In the direct vent systems ,there are some limitations as to how long the exhaust ducting/fluepipe can be. The one I’m more familiar with has a maximum run of 20 feet. Above that, the pipe resistance reduces flow too much. See: