Your First Heat Run of the Season: What to Do Before It Gets Cold

Why Your Furnace Smells Like Dust in October

Every fall we get calls from homeowners convinced something is burning. Usually it isn't. Over six months of sitting idle, a fine layer of household dust settles on the heat exchanger and the burner assembly. The first time that metal comes up to temperature, the dust burns off. It smells like a hot iron or a scorched vacuum bag, and it is completely normal.

What matters is how long it lasts. A dust burn-off fades within fifteen to thirty minutes and never comes back that season. If the smell is still there on day three, or if it smells sharp and electrical like hot plastic, that's a different conversation and worth a look from a technician. And if you ever smell sulfur or rotten eggs, that isn't dust at all. Leave the house, then call Washington Gas from outside.

The Five-Minute Walk-Around

Start with the filter, because it is the one thing that undoes everything else. A filter that spent the summer catching pollen and construction dust will choke a furnace just as effectively as it choked your AC, and a starved blower is the fastest way to overheat a heat exchanger. Write the date on the new one with a marker. It takes two seconds and it settles every future argument about when you last changed it.

Then walk the house and open every supply register, including the ones in the rooms nobody uses. Closing vents does not save money on a residential system; it raises static pressure and makes the blower work harder. Move furniture and rugs off the returns while you're at it. Outside, clear the leaves away from your heat pump or condenser and give it a couple of feet of breathing room on all sides. Oaks and maples drop fast here in October and that unit still needs airflow in heating mode.

Last, look at the condensate drain near your indoor unit and make sure it isn't clogged, and glance at the flue pipe where it exits the house to confirm nothing has nested in it over the summer. If any of that looks wrong to you, don't guess. Our HVAC maintenance service covers all of it as part of a standard visit.

Run It for 20 Minutes on a Mild Day

Switch the thermostat from cool to heat, then set the target about five degrees above the current room temperature so the system actually commits to a full cycle. Now go stand near the equipment and pay attention. You want to hear the sequence: a click, the igniter or the reversing valve, then the burner or compressor, then the blower a few seconds behind it. Warm air should reach the registers within a minute or two.

The things worth noting are the ones that are new. Grinding or squealing from the blower, a rhythmic clicking that never resolves into ignition, a boom instead of a smooth light-off, or short cycling where the unit fires and quits repeatedly within a few minutes. If you have a heat pump, also confirm it isn't jumping straight to emergency heat — running on backup strips in 50-degree weather is expensive and usually means the outdoor unit isn't doing its job. That's worth a call to us about heat pump service before the bills arrive.

Do this in September and a bad igniter is a Tuesday appointment. Do it in January and it's a cold house. If you want the mirror image of this checklist for the other end of the year, we wrote one for the spring changeover from heat to cool as well.

A Local Crew, Not a Call Center

We work out of Annandale, and that isn't a mailing address on a website. It means the truck heading to your house in Falls Church or Springfield is already inside the Beltway, and the person you spoke with on the phone knows the neighborhood you live in. Paul is on jobs himself, which is unusual for a company our size and is the reason so many of our reviews use his name.

It also means we know what's in the housing stock here. The 1960s split-levels in Annandale with the original ductwork, the attic air handlers all over Burke and Fairfax Station, the townhouse mechanical closets in Alexandria where nothing fits. If you're outside our immediate area we'll tell you honestly whether we're the right call. Our furnace repair in Alexandria, VA and HVAC maintenance in Falls Church pages cover what we do in each city.

What Our Fall Calls Actually Look Like

These are photos from our own jobs around Northern Virginia — attic air handlers, furnace flue venting, leak testing at the fittings, condensate lines run properly the first time. Most of this is work you'll never see once the panels go back on, which is exactly why we photograph it. You should be able to look at what you paid for.

Click any image to open it full size. If your equipment looks noticeably worse than what's here — heavy corrosion, duct tape holding things together, water staining under the unit — that's worth showing us before winter starts.