Smell might be coming from ductwork

There has been a really bad smell in my house lately.

It literally smells like a public toilet.

Not just any public toilet either. A public toilet at a ball game or large even like that. The stink is terrible. I have looked all over the house and can’t find the source of the smell. I have cleaned under the couch, under the refrigerator, and washed all of the linens. Nothing has helped. The smell remains. A good friend of mine said that I might want to look into getting my HVAC system serviced. She said that she had a similar experience a year ago and that it turned out to be her ductwork system. She had HVAC technicians come and clean out the ductwork and service the whole HVAC system. She said they even installed a special carbon filter. The smell went away and never came back. Now she has her HVAC system serviced at least once a year. A smelly HVAC system would explain the smell in my house I suppose. It would make sense. After all, the smell is bad in every single room of the house. Now that I think of it, the smell is worse when the heater is on too. I guess I am going to have to hire an HVAC company to come out and take a look. I hope they don’t charge too much though. However, at this point, I am willing to pay just about anything to get rid of that smell. It is only getting worse and I can’t live like this.
heating company