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: 7692

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 

Videos

  • Add Videos
  • View All

Latest Activity

John Wagner 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
4 hours ago
Home Energy Magazine posted a blog post
5 hours ago
Jim Tenhundfeld posted a discussion

LED's and motion sensors

When completing an audit, a customer told me that when he installed a LED lamp in his outdoor…See More
10 hours ago
Barbara Smith posted videos
yesterday
CharlieK posted a discussion

Eco-Cottage Program Applauded By Housing Groups, Suppliers & Lenders

AmeriSus a leading player in the eco-kit home business kicked off a new program on MLK-day which…See More
yesterday
Diane Chojnowski posted a discussion

Call for Nominations: Tony Woods Award and Building Performance Hall of Fame

The Building Performance Institute, Inc. (BPI) is seeking nominations for the 2017 Tony Woods Award…See More
yesterday
Diane Chojnowski added a discussion to the group 1000 Home Challenge
Thumbnail

January Webinar: Intro to the 1000 Home Challenge

The January Intro to the 1000 Home Challenge webinar will be  Friday, Jan 20 at 10-11:30 AM eastern…See More
yesterday
Diane Chojnowski's event was featured
Thumbnail

Introduction to the 1000 Home Challenge Webinar at Eastern Time

January 20, 2017 from 10am to 11:30am
The January Intro to the 1000 Home Challenge webinar will be  Friday, Jan 20 at 10-11:30 AM eastern…See More
yesterday

Home Energy Pros

Welcome to Home Energy Pros – the unique digital community by and for those who work in the home energy performance arena.

Home Energy Pros was founded by the developers of Home Energy Saver Pro (supported 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. Please honor our Guidelines

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service