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!

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!

Views: 1353


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.  

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Colin Genge posted an event

Home Efficiency Forum at Courtyard Portland City Center

October 21, 2015 at 8am to October 23, 2015 at 5pm
Home Efficiency Forum (formerly known as Boot Camp) brings Northwest Raters, Verifiers, builders…See More
5 hours ago
MCX posted a blog post

Good HVAC in Arlington, Texas

Arlington is a city in the U.S. state of Texas, within the Dallas–Fort Worth–Arlington metropolitan…See More
5 hours ago
Profile IconRichard L. Sanderson and Diane Jackson joined Diane Chojnowski's group

Home Energy Pros on Twitter

We've created a twitter list of members of Home Energy Pros who tweet!See More
6 hours ago
Diane Jackson commented on Diane Chojnowski's group Home Energy Pros on Twitter
"@addisonhomes "
7 hours ago
Diane Jackson posted a blog post
7 hours ago
John Gillis replied to John Gillis's discussion Energy Savings of Whole House Fans vs. Air Conditioners in SoCal Featured on New 'Ask This Old House' Season in the group News & Announcements
"Hi Eric. Thanks for the response. If you wouldn't mind calling/e-mailing Nelson Warner or…"
13 hours ago
Profile IconShandi Whited, Noah Sanders, Edward G Fahrenkrug Jr and 2 more joined Home Energy Pros
14 hours ago
Alan Gindt replied to Alan Gindt's discussion Minneapolis Blower Door System for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Bob, sorry but it has been sold"
15 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service