By now we all are aware (or at least should be) that call-backs are a bold faced robber of profits and success. Not to mention it's damaging to the reputation of the company and brands involved. Below is my recommend list of things your company, and technicians can adopt as policy  to hopefully, help eliminate the dreaded call backs.

Be thorough! We hear this a lot from technicians "We've checked EVERYTHING". If this is true, likely you would have stumbled across the issue. Truly check, double check and triple check your readings. If you are not taking or documenting readings and measurements, START! These measurements and readings can, and in most cases will, help you find the "Smoking gun". Get this information on EVERY visit, regardless of how many times you've been there. You might find the red-flag you're looking for. 

Look around. Try not to be "appliance focused". The unit is attached to multiple systems, gas, electric, drain, duct, vents, and the home. If any one of these other systems is not working correctly, the appliance will not perform correctly and/or fail.

Venting, drains, and high winds can cause pressure switch lockouts. Verify size, lengths, cleanliness, terminations and how they are built. No sags or dips, verify proper pitch and support. Pressure switch tubes on the furnace can sometime collect moisture. Re-route tubing in these cases so that moisture cannot trap.

In the case where the furnace is "acting weird", Eliminate ALL outside influence tied to the 24vac circuit. This includes, humidifiers, uv lights, air cleaners, wet/drain switches, and even the thermostat. See if the unit seems to run better with just a R-W jumper.   

Airflow. The second biggest problem to our industry, next to lazy. Verify that the airflow is set correctly for the system. Measure TESP (total external static pressure) and reference the blower charts in the manual. You might find that the furnace is too big for the duct system or even the home. Eliminate restrictions. Air filters can be restrictive to the air system so make sure its sized properly. Dirty coils, closed off registers, zoned systems on single stage equipment ect. All contribute to airflow issues and system failure. 

Incoming voltage can have an impact as well. Make sure it is in line and stable. Occasionally whole home stand by generators can cause equipment to not work properly. 

Flame sensing. Poor or missing grounds are the leading culprit. Measure the microamp signal, typically 2-7 microamps dc is desired. If flame sensors are repeatedly needing to be cleaned, check the environment or combustion air. This is an environmental issue, not something wrong with the furnace. The sensor is getting dirty for a reason, figure out how and why.

Dispatchers and service managers, DO NOT RUSH YOUR TECHNICIANS! The technician must be clear headed to be thorough. The systems now-a-days are a bit more complex with control boards, extra wires and accessories. They must be able to have time to investigate and trouble shoot. Again, the goal is to solve the problem the first time, eliminate a call back, and avoid that awkward phone call from the homeowner. An extra hour not spent on the job, could cost you many more hours and dollars down the road. 

Continue your education. There is a ton of training and learning opportunities available to you. NEVER stop learning and master your trade. Technology and equipment is changing constantly, stay on top of these changes and ahead of the curve. Don't be afraid to repeat a class. Just like equipment, sometimes a "tune-up" is needed. 

Good luck out there!

Carlos