Updated: Jun 20, 2021
This time I will tell you how important it is to change the filter every 2 months and at least use it.
I was initially called because the blower Fan was running very loudly at maximum speed. When I arrived, I didn't like it right away, because the system was almost new, and it had a Smart motor that simply could not work at such a high speed. It turned out that there was a hidden additional filter in the system, which was completely clogged, plus the evaporator coil was also clogged completely. Precisely because the engine could not blow through this restriction, the engine turned on maximum speed.
Before that, the house had other owners who had pets and, apparently, they did not change the filter for a while, which caused the evaporator coil to clog. Also, an inflatable ball was found in the coil, which is restricted to one part of the coil, which is why I realized that for some time the filter was not used at all
Usually washing the evaporator coil with chemicals costs $ 250, But this time the owner had to pay five times more, in fact, as for replacing a new coil, since the specific location of the coil did not allow it to be easily opened or removed and we had to unsolder the pipes, evacuate the refrigerant, and then solder it back.
Since the system was only 5 years old, it made sense to do the so-called repair. But if the system was old, then you would have to think about whether it is worth paying about $ 1000 for washing the coil.
This is why every time during an inspection, I ask the owner the necessary questions about filter replacement, filter location and much more.