Seems pretty elementary doesn't it?  What should be a simple safety check on fossil fuel burning appliances, particularly for boilers with regards to ease of inspection, often is assumed with complacency or even goes unchecked.  I know everyone's maintenance schedule is packing up in the Northeast with the cold snap this week, so Technicians Take Heed!

There are many indicators that should trigger the phrase: "Check the flue!"  I always measure the draft in the flue of a natural draft, 80% appliance.   Too high or too low of a draft both can be an issue.  HVAC Contractors tend to focus on the 'too little draft' by installing chimney liners, completing Combustion Appliance Zone and CO testing.  Of course this condition could be the most dangerous, so I can't blame them.  Who ever expects to pull the flue off the boiler, look into the chimney and see what is pictured?  There must have been 40 years of garbage piled up!  Really is a spectacular thing that after all the years of maintenance I have yet  to become complacent with the Flue. 

Did you know the draft of the chimney is very dependent on the temperature difference between the flue gas and outside.  The greater the temperature difference, the better the draft (generally speaking).  This means the draft may be just fine on a cold WInter night, yet spill gases on a warm Fall afternoon.  Conversion warning: 25 Pascals = .10" w.c.  I know: metric, really?...Trust me, the rest of the world has the real gripe when they see standard measurements.  I bet your electronic manometers or even magnahelics (whatever you are using for draft measurements) have this scale.  Take a look at this chart supplied by Building Performance Institute (T_Out is your Outdoor Ambient Temp), start testing, and be sure that boiler will be safe all year long.  Oh, and don't forget about the water heater too!

 

 

BPI.org

The draft was just fine on this older, larger than most boilers (-.03"w.c.).  Except how long before that chimney became a real problem?  I have to tell everyone: I have found birds, nests, even a squirrel in a 90%+ flue.  Yes, that was a rotting mess to cut through with a hacksaw in a half-finished basement.  Always test the draft, measure the CO, and look into the flue/chimney.  You may just be surprised one day; possibly save someone, or maybe a home!

http://excessair.blogspot.com/2013/09/check-flue.html

Views: 1945

Comment

You need to be a member of Home Energy Pros to add comments!

Join Home Energy Pros

Comment by Bob Blanchette on October 8, 2013 at 4:46pm

ALL dryers should have the duct checked annually. Electric dryers will set the lint on fire if the heating element doesn't burn out first.

Comment by Dennis Heidner on October 8, 2013 at 3:23pm

Good article..

If the homes have a natural gas dryer - check the flue -- in this case the vent line is as important.  Long drying times are symptons of a clogged dryer vent... and when its natural gas -- that means the flue is not operating efficiently.  

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Evan Mills commented on Tom White's video
Thumbnail

The Impact of Green Buildings on Cognitive Function

"Good to see work like this going on.  Findings seem qualitatively consistent with what…"
5 hours ago
Keith Burrows's blog post was featured

What Happens When Home Performance is Made Visible?

“I don’t know” or “probably not” are the most common responses I hear to the question, “is your…See More
11 hours ago
Sarah Holloway posted a video

Don't Lose Your Marbles. Use DASH!

Are you a growing energy rating business? DASH is everything you need to operate your company.
11 hours ago
Profile IconTim Grant and Glen Davison joined Home Energy Pros
12 hours ago
Rosie Smith replied to edward knight's discussion Minneapolis duct blaster for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Hi Edward...is this equipment still available?? Thanks, Rosie Smith Fresno,…"
yesterday
Rosie Smith joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
yesterday
Jim Gunshinan liked Tom White's discussion Home Energy Reader Survey
Tuesday
Tom White posted a discussion

Home Energy Reader Survey

Home Energy wants to serve you better.  Please …See More
Monday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service