In a recent blog post about fall maintenance for Minnesota homeowners, I mentioned having your furnace inspected / tuned up by a qualified heating contractor annually. One reader sent me an email asking if this was really necessary - here's his original question:
I think these are great questions worthy of a post all on their own.
Are annual furnace inspections really necessary? Furnace manufacturers all recommend annual inspections and maintenance by a qualified technician. They also have language in their warranties saying that damage to the units caused by improper maintenance is not covered under warranty. Does this mean that an annual furnace check-up is really required, or the warranty is voided? Probably not, but it's recommended. The best analogy I can think of is going to the dentist every six months for a check-up and cleaning; probably not necessary, but recommended.
I've heard some HVAC contractors recommend getting newer furnaces checked every other year, but once they're over ten years old, have them checked annually.
What do HVAC technicians actually do to the furnace to "tune" it up? It depends. According to Chris Jirak, a heating guy who has worked for several firms in the Twin Cities over a period of 25 years, the service you get when you purchase a $29 Groupon is going to be quite different from a $200 "tune-up". Chris said that every contractor he has ever worked for has had carefully worded language with subtle differences in the descriptions, making it nearly impossible to compare services between different heating companies. A few services you may have heard of are "safety check", "certification", "check-up", "tune-up", "basic tune-up", "complete tune-up", and "annual maintenance check-up."
The services provided by different heating contractors will vary, depending on who you call and what you pay. For example, I recently inspected a boiler in Minneapolis that had a missing flue cap at the exterior, an undersized vent connector, and a rust hole in the middle of the cabinet that was leaking carbon monoxide in to the home.
Just a couple months prior to this, a heating contractor had come out to inspect the boiler and given it a clean bill of health. The receipt for the service call had been left on the kitchen table, so I took a photo of it.
The point is that there seems to be no industry standard for a furnace (or boiler) tune-up, so what's included in a "tune-up" will vary greatly from company to company. If you're going to hire a heating contractor to do a tune-up on your furnace, ask them what they'll be doing. Included below is a partial list of generic stuff that different furnace manufacturers recommend be performed annually a qualified heating technician:
