Arkansas HVACR NewsMagazine November 2025

HVACR NewsMagazine November 2025

State National Chapter News

mechanical stress being placed on other components in the system, fuel fired appliance errors most likely result in poor performance, equipment failure and possible CO production. Few installations mirror the testing criteria found on the manufacturing test platform. Use of the analyzer will give the btu yield, tell you if flue temperatures are out of range, provide information to maximize heat exchange and whether the gas valve is leaking. There are basic check lists to make sure nothing is overlooked from many sources listed later. The items listed here are by no means complete or in proper order. We are just hitting the high points. Building Performance Institute (BPI) recommends you start evaluating the system visually from the street looking at combustion venting if visible. Next is the task of checking a personal CO monitor and zeroing the combustion analyzer outside before entering and keeping an eye on the tool. Once inside a primary observation of an open flue is mandatory. A cursory inspection of the filter, blower wheel, general condition of the furnace may be a prudent step prior to putting the furnace through its paces. Inspection of the system should include mechanical and electrical connections, signs of corrosion due to combustion spillage or condensation due to temperature change or roof and vent leaks. Proper slopes on vents and condensate drains should be noted.

Next is the Combustion Appliance Zone or CAZ testing with a manometer. This test measures pressure differentials in a worst-case scenario to make sure competing appliances or vents will not interfere with proper drafting of larger fuel fired appliances.

Educating the homeowner of findings and the importance of CO monitoring full time is a final step. Fast forward a few years and you will see temperature sensors in the flue and heat exchanger, O2 sensors and a

processor in the furnace controls for full time burner management like similar to the automotive industry today.

Solutions

There are many avenues for training of related to carbon monoxide poisoning and combustion safety and everyone working on combustion appliances should have a grasp of the fundamentals. The National Safety Council, U.S. Fire Administration, OSHA and the NFPA provide basic tips and safety training. Esco digs deeper and most manufacturers like Bacharach, Field Piece, and Testo provide a general knowledge of CO training with respect to safety practices and specific to their tools. Building Performance Institute (BPI) does a good job of identifying deficiencies when it comes to combustion in combination with safety and a perspective of building science.