I am generally a smart and handy person when it comes to little fixtures around my home.
I rarely call in any servicemen for assistance, especially if I can get a manual and follow the troubleshooting and fixing procedures.
However, in some complex cases where professional assistance or know-how is required, I leave the tasks to the experts. So this one time, I noticed that my furnace was suddenly behaving strangely. It kept going on and off. While I knew that the thermostat setting allowed it to have an on-off cycle, it was not supposed to happen as it did. The heating cycle was to take a few hours until optimum temperatures were attained before it turned off for a while. But this was not what my furnace was doing. It was going on and off within seconds, and no amount of resetting seemed to resolve this issue. I knew that this short cycling was an indication that something serious was off. I talked to my HVAC technician, and he suspected an issue with airflow. Since not enough air was getting out of the furnace, it was overheating and switched off before the optimum temperatures were attained. With the guidance of the HVAC professional, I changed the filters to allow better airflow. I went for better quality flyers as recommended by the HVAC business experts at my local store. Fortunately, this seemed to work. It turns out that the filter that was in my furnace before would feel up too quickly, causing restricted airflow. In case this had failed, then I would have hired an HVAC contractor to fix the issue.