Exhaust and intake for a high efficiency gas boiler
We just had a high efficiency gas boiler installed in our 3-story rowhouse. Our heating contractors ran two PVC pipes into our lined flue. One of them continues all the way up to the roof and out the chimney; the other stops just inside the flue, on the cellar level. We’re not sure which of…
We just had a high efficiency gas boiler installed in our 3-story rowhouse. Our heating contractors ran two PVC pipes into our lined flue. One of them continues all the way up to the roof and out the chimney; the other stops just inside the flue, on the cellar level. We’re not sure which of the two pipes is the air intake and which is the exhaust. The flue is wider than the PVC pipe, so air can travel around the long pipe, down (or up) through the flue and into (or out of) the boiler via the short pipe.
The Keyspan guy came round today to turn the gas on, but refused to do so when he saw the way the venting and intake were set up. Anyone know who’s right? Anyone, perhaps, by the name of Master Plumber??
i’m not sure it’s code to use your chimney for air intake in new york city. i know you can do it elsewhere but i’ve been told not in nyc.
Although, I prefer Burnham boilers, Weil-Mclain and Lochinvar make boilers (the Ultra and Knight respectively) that can vent 90 feet vertically.
In most cases you can use your current chimney as a chase to drop two 4-inch pipes down from the roof to the boiler and not get involved with clearances from windows and doors.
More may be coming soon as these seem to be selling well in our area.
we have a HE boiler installed. it’s been a nightmare because the plumber that installed it was inexperienced with these boilers. (very long story!!) I learned along with him that there is a very specific math equation; size of pipe and cummulative length that these intake and exhaust pipes can run to operate the boiler properly. ours run out and up the back of the house and the shorter one is the intake and the taller/longer one is the exhaust. the height of the intake needed to be above potential snow drifting and the exhaust runs up one story and out away from the house along the side of a deck.
our brick flus where in very bad shape and not an option to vent anything through there. we redid one fireplace and this flu needed to be lined with a round stainless steel pipe which they can retrofit inside the flu. (as mentioned above) wasn’t too big a deal.
good luck
Related question: Which of the high efficiency boilers are most suitable for NYC? (taking into account intake exhaust requirements, building codes, etc.)
I like guest 9:47’s answer and as much as I hate to admit it, Keyspan did the right thing. The installation is incomplete.
Have the venting installed as per manufacturer’s instructions which is the criteria by which the appliance was given the green light (MEA number) for use in NYC.
Anything short of that and your safety is at risk.
Don’t quite understand your post, but we installed a high efficiency boiler a few years back, turned out it was too strong for the existing chimney flue, the emissions turned to acid, began leaking on the third and fourth floors, total mess. We too had to break into all the flues and install a special stainless steel tube and install a new chimney.
Be careful, be very careful.
Homeowner here who recently installed a high efficiency munchkin gas boiler with pvc intake & exhause pipes. I am pretty sure that your plumber is wrong and suggest that you call the manufacturer and read the installation instructions carefully. Our installation manual was reasonably straighforward when it came to specifying the installation on venting etc -> you probably need parallel pvc pipes running all the way to the roof, and maybe needs to be 4″ pipes (not standard 3″ pipes) depending on the distance from teh boiler to the roof. The pvc should be a particular type (I cna’t remember but maybe schedule 40?). Honestly it proved to be quite a bit work for us to get it set up correctly incl requiring opening of the flue on every floor
This is a serious safety issue that you should be very careful with for your own sake & that of your neighbors etc. Also probably effects functioning / efficient functioning of boiler.
Good luck.