Waking a furnace that slept through hurricane season

Nine idle months in wet air

Think about what a furnace in Cypress Knoll actually experiences in a year. From the first warm week in March through most of November, it doesn’t fire once. The air handler blower runs through it constantly, pulling 76-degree, 90-percent-humidity air across burners, a flame sensor, an ignitor and a heat exchanger that never get hot enough to dry out. Condensation forms on cold metal in the garage every August morning. Salt rides in on the breeze on waterfront sections. Mud daubers find the flue. Rust blooms on the burner tubes.

Then a cold front drops through Flagler County in early December, the thermostat calls for heat, and a machine that has been corroding for nine months is asked to ignite a gas-air mixture correctly on the first try.

Some do. A lot don’t. The ones that don’t become January repair calls, and the ones that half-do, lighting with a yellow flame or a delayed whump, become something worse.

That’s the whole case for a fall furnace visit in a town with a two-month heating season. It isn’t about a long winter. It’s about a long, damp summer.

This is not a filter change with a clipboard

Let’s be clear about what a furnace maintenance visit is not, because the cheap version exists and it’s worth less than nothing.

It is not a glance at the filter, a thumbs-up, and a sticker. It is not a “free inspection” that ends with a replacement quote for a furnace that was fine. It is not something to do on a gas or propane furnace without a combustion analyzer and a carbon monoxide meter, because the dangerous failures on these appliances are invisible. And it is not a repair; if we find a failed part, that’s quoted separately and you decide.

What a furnace check actually covers

For a gas or propane furnace in the Peoples Gas sections or on a west-county tank:

• Heat exchanger inspection, with a camera on older units, for cracks and corrosion.
• Burners pulled, cleaned and reseated; flame sensor cleaned and its signal measured.
• Ignitor inspected; gas valve and manifold pressure checked, propane regulators included.
• Flue and draft checked for blockage and proper venting; nests removed.
• Combustion analysis: oxygen, carbon monoxide, flue temperature, efficiency.
• Carbon monoxide measured in the supply air and the living space.
• Limit and rollout switches tested; blower wheel and motor cleaned and amp-tested.

For an electric furnace in a boom-era air handler across Lehigh Woods, Quail Hollow and Seminole Woods:

• Each strip element amp-tested; sequencers and relays checked for timing and burnt contacts.
• Thermostat configuration verified so strips engage only as backup, never as the first stage.
• Blower, filter, static pressure and, since the cooling coil shares the cabinet, the drain and float switch.

Either way, you get a written report: what passed, what’s wearing, what we’d plan for.

Schedule a furnace check

The visit, start to finish

1. Arrival and interview. Any smell, noise or short-cycle you noticed last winter goes on the sheet.
2. Cold inspection. Power and gas off. Cabinet opened, exchanger looked at, burners and sensor removed and cleaned, blower wheel inspected, wiring tightened.
3. Reassembly and first fire. Furnace brought up from a cold start, exactly the way December will do it. We watch the ignition sequence for hesitation.
4. Measurements under load. Gas pressure, temperature rise, flame signal, combustion readings, CO in the house; or, on electric, stage-by-stage amperage.
5. Controls. Thermostat calibration and heat settings, limit switches, safety switches.
6. Report and calendar. Findings in writing, the spring air-conditioning visit penciled in.

An hour, give or take, for a furnace that’s been maintained. Longer for one that hasn’t seen a technician since it was installed.

Three things to do before the truck arrives

• Clear the furnace. Garage furnaces in Palm Coast tend to disappear behind beach chairs, coolers and the second refrigerator. We need the front panel and about three feet of floor.
• Test your CO detector. If you don’t have one on each level near sleeping areas, buy one this week. We’ll check it, but we’d rather you already had it.
• Run the heat once. A day or two before the visit, set the thermostat to heat for ten minutes. If it does something strange, you’ll be able to describe it; if it does nothing, we’ll know to bring parts.

Why Palm Coast furnaces get skipped, and why they shouldn’t

Furnaces are a minority here. Most of the city heats with heat pumps, and the gas furnaces in Palm Harbor, the Woodlands and Flagler Beach, plus the propane units out toward Espanola and Daytona North, are easy to forget because they do so little. That’s precisely what makes them risky: a cracked exchanger on a furnace that runs thirty nights a year goes unnoticed for seasons. Carbon monoxide doesn’t need many hours. One fall visit a year, with the analyzer in the flue and the meter in the hallway, is the price of not thinking about it the rest of the time.