Things used to be so easy when working in this business back in the day. When carrying tools for some old timers, I remember some replacing an air filter and kicking the furnace while saying"Yup, still here!" Maintenance these days, for great reason, has taken a more efficient operation mentality, mainly because energy prices have started to affect our wallets. These days, 68% steady state efficiency oil boilers and gas furnaces with high carbon monoxide readings mean something. But, does it necessarily mean we must replace the furnace, boiler, hot water heater, etc.?
I heard a situation a couple weeks ago where a representative of a local gas company, whether or not he was a subcontractor I cannot be sure, completed some maintenance on a gas boiler that he ended up shutting down due to a high CO reading. Most building analysts know that 26-100 ppm CO (in the flue, at steady state) means repair is necessary (see Combustion Safety Test Procedure, BPI.org), and to call a heating professional. So why did this tech shut down and tag this boiler for replacement? Was it actually a sales tactic?
High Carbon monoxide readings tend to point to what I like to call "unbalanced combustion". You see, it could be due to lack of combustion air, too much gas, or too much excess air (not my blog, please keep clicking!). No matter how you slice it, the combustion process is out of balance. I have seen high CO readings for draft inducers failing, secondary heat exchanger condensate drains clogging, improper manifold gas pressure, incorrectly adjusted draft dampers, you get the idea! None of these reasons mean the equipment has to be replaced, but the recommendation could be made.
The boiler I started talking about earlier had a manifold gas pressure twice the recommended value. There was too much combustion air due to a lack of understanding and/or measurement. Since he took the readings, I doubt it was the latter. Looking at the flame on a 90%+ AFUE appliance will never be a justified reason to crank up the manifold gas pressure. If you cannot measure with a combustion analyzer, or even a manometer, at least clock the gas meter before you start creating high CO2 and CO outputs. You are the professional and the homeowner is paying you for the expertise. Please, don't recommend replacing a boiler your company may have installed just a a couple years ago!
http://excessair.blogspot.com/2013/01/high-co-reading-now-what.html...

Views: 1568

Comment

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

Join Home Energy Pros

Comment by tedkidd on January 10, 2013 at 9:26am

I can't answer how much of red tag was a sales tactic, but search CO poisoning on google news, or create a news alert and you'll see news reports of deaths and people hospitalized daily.   

Any device disconnected from the flue is dangerous.  That means any natural draft appliance, because they are all disconnected from the chimney they supposedly vent through.  

Here's a great blog by David Richardson on the subject: http://bit.ly/davidrDrafthoods 

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.

Latest Activity

Rob Madden, Solar Home Broker posted a blog post

Phoenix 3rd Quarter Solar Resale Statistics Continue to Impress

Phoenix solar home sales were up during the third quarter of 2014, including the resale of homes…See More
5 hours ago
Everblue posted a status
"Green job alert! Energy Auditor in Baltimore, MD with Advanced Green Home Solutions. Check it out: http://bit.ly/1xhQuXO"
6 hours ago
Chris Clay replied to Isaiah Borel's discussion Blown Cellulose VS Blown Fiberglass in the Attic
"The Cold Climate Housing Research Center in Fairbanks, AK has alot of information about this…"
6 hours ago
Richard L. Sanderson replied to Bud Poll's discussion Inconsistant Local Authority
"Bud: I like the idea of a third party review board. My own experience in local government is that…"
14 hours ago
Matthew Lutz commented on Kaplan Clean Tech's blog post The Difference Between Home Inspection and Energy Auditing [Infographic]
"I would have to agree with Steve on this.  I am a Certified Energy Manager and have performed…"
19 hours ago
Matthew Lutz joined Diane Chojnowski's group
Thumbnail

Hall of Shame

In this group, members share an array of images from the field, showing the kinds of issues…See More
19 hours ago
Matthew Lutz replied to Kari Sauder's discussion Easy Water Heater Venting in the group Hall of Shame
"I have been in the HVAC trade since 1986. I have recently completed a Home or Real Estate…"
19 hours ago
Susan E. Buchan posted an event

EEBA Houses That Work at Hilton Asheville Biltmore Park

November 3, 2014 from 8am to 4:30pm
Registration: 8:00 amSession: 8:30 am to 4:30 pmWorkshop Covers:Introduction to EEBA and its…See More
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service