My mom and dad have a weird smell coming from their air vents

My mom and dad have a weird smell coming from the air vents in their house. Apparently, this has been going on for a while without me knowing about it. My mom finally called me the other day and she started complaining that their whole house just smells like hot garbage or something. I asked her all the normal questions about it like whether or not they had a dead rodent stuck in a ventilation duct or something, but she said no. She did say that every time they turned the thermostat up or down, they noticed the awful smell. She said that it didn’t matter whether it was the heating or the A/C, either. She and my dad had tried running both the furnace and their central air conditioning system and the smell remained the same. I really had no idea what the problem could be, and so I finally told her that she should just call her local heating and cooling company to see what they could tell her. Apparently, the HVAC technician that she spoke to said that sometimes your ventilation ducts can get mold and mildew growing inside of them. Whenever this is the case, there can be some really bad smells that come from the air vents when the HVAC system is running. The HVAC technician seemed to think that this was what was happening at my parents’ house. She scheduled an appointment for them to come do a complete professional air duct cleaning on her HVAC system. Hopefully, that will clear up the problem and their indoor air quality will be back to normal soon.

Heating maintenance