As HVACR technicians, assessing whether the furnace we’re servicing is working efficiently is critical to understanding the overall health of the HVAC system — and to the success of our service call.

A few months ago, we discussed seven combustion testing skills of elite service technicians. The first skill to master was the most obvious — combustion testing. The gases that a combustion analyzer ...

The analysis is essential, especially for evaluating the air-fuel ratio, surplus air, products of combustion, and unburned constituents. As this is a pivotal factor in environmental preservation and ...