Recommended location flue gas probe

Sean_16

Rick:

THanks very much. Option 1 applies, so I'll go with that.

Sean

Sean_16

I'm borrowing my job's Bacharach Combustion Analyzer (nice toy) to test my home's gas boiler. For a smaller boiler, what's a good location for the flue gas probe? Thank you.

Rick T

gas combustion test

You want to test undiluted flue gas.
So, depending on what type of unit you have, you want to test before dilution air enters the flue gas stream.

1. if it is an older unit with a draft hood, make a test hole between the heating unit and the draft hood opening. If it is a forced air unit, you may have to test the exit of each "clam shell" heat exchanger visible under the draft hood.
2. If it is an induced draft unit with an induced draft fan,
test in a piece of straight pipe after the fan a couple of flue pipe diameters. Seal up the hole well afterwards.
3. If it is a condensing unit with plastic flue pipe, the Bacharach unit won't really test it properly. Once the unit condenses, extra efficiency is added taking it up to 90% or more. You could measure the stack temp and CO2 or Oxygen for interest's sake, but be sure and seal up the hole afterwards.

Be sure to test the CO2 (or oxygen) stack temp, draft (varies), and Carbon Monoxide.

Rick

hr

Go to this site first!

spend an hour and read all the info here. It will help a ton

http://www.bacharach-training.com/

hot rod

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Sean_16

hot rod:

great resource, thanks very much! i actually do use the PCA on the Cleaver Brooks boilers that I work on (CB250), but just because my home boiler is smaller, i don't like to make any assumptions that I know everything there is to know about it. totally different animal.