Where the furnaces are in Clay County, and one January day spent fixing them

Which eras of house actually have a furnace here

Orange Park is heat pump country, and a furnace is the exception. Where the exceptions sit depends on the house’s vintage and what fuel could reach it.

Gas furnaces live where TECO Peoples Gas runs a main, which in Clay County is a limited footprint: parts of Green Cove Springs, where a transmission line was extended in 2015-16, and scattered newer streets. The Victorian spa-era homes near Spring Park and the 1990s and 2000s subdivisions that happened to get gas service are the core of it.

Propane furnaces are the rural answer. Middleburg acreage, Clay Hill, Penney Farms, the Keystone Heights lakes: a tank in the yard, a delivery truck in winter, and a furnace that is often paired with a straight-cool air conditioner because the home was built before heat pumps were the default.

Oil furnaces are rare survivors in a handful of mid-century homes, including a few along River Road in the historic district, usually with a tank that is older than the owner.

Electric furnaces, meaning a blower cabinet with a bank of resistance strips and no heat pump, are the most common “furnace” in the county by far. They sit in 1960s-80s block ranches around Kingsley Avenue, through Bellair-Meadowbrook Terrace and Ridgewood, wherever the original builder put in cooling-only with strip heat.

Each kind fails its own way, and the January route visits all four.

A January furnace day, from Green Cove to Keystone

First light, Green Cove Springs. A gas furnace in a tall-ceilinged 1890s house near Spring Park clicks, lights and dies after a minute, over and over. The homeowner has been doing that cycle since 5 a.m. The flame sensor is coated with a season’s worth of oxide and can’t see the flame it is standing in. Cleaned, tested, combustion checked with the analyzer, carbon monoxide at the register read and recorded. Twenty-five minutes.

Mid-morning, Middleburg. Propane furnace on acreage off Black Creek, no heat, no noise. The inducer motor has seized; the pressure switch never closes; the board never opens the gas. Universal inducer on the truck. While it’s open, the heat exchanger gets a camera look because the home flooded in 2017 and the furnace was dried out rather than replaced. The exchanger is clean. The owner hears that it was checked and why.

Early afternoon, Bellair. An electric furnace in a 1972 block ranch heats half the house. Two of four strip elements are open; the sequencer for the second pair failed, and nobody noticed in a mild December. Sequencer and elements replaced, amperage confirmed on all four, a note that the breaker has been weakened by a summer of surges and should be looked at by an electrician.

Dusk, Keystone Heights. A propane furnace on a lake lot with a yellow, lazy flame and a sooty burner compartment. Burners pulled and cleaned, gas pressure checked against the nameplate, combustion analyzed. The house has well water with sulfur in it, and the smell had been masking something that needed attention. Combustion comes back clean; the owner gets a carbon monoxide alarm recommendation in writing.

The combustion kit, and what each tool is for

What Clay County furnaces are usually doing wrong

• Dirty flame sensors, because the furnace sits idle for nine humid months and oxidizes.
• Failed igniters, cracked by the cycling that a dirty flame sensor causes.
• Seized inducer motors on furnaces that haven’t turned in ten months.
• Open strip elements and failed sequencers in electric furnaces, usually discovered on the first real freeze.
• Weak propane pressure at the end of a tank, mistaken for a furnace fault.
• Clogged condensate traps on high-efficiency gas furnaces; the same algae that plagues air conditioners here grows in a furnace drain too.
• Flood history: furnaces in the Black Creek and Doctors Inlet low spots that went under in 2017 and have rusted from the inside since.

Get a furnace tech on the route

After the diagnosis: fix, defer or retire

Most of the list above is fixed on the first visit and costs little. The price is given before the work, and the hour of the day doesn’t change it. A few findings end the repair conversation and start a different one: a gas or propane furnace with a cracked heat exchanger, which is a carbon monoxide risk and not a part we will patch; a furnace that has flooded and is rusting through; an oil furnace whose tank is failing. In those cases the quote for a replacement comes with a real question attached, which is whether this house should have a furnace at all or whether a heat pump would heat it for less and cool it as well. In a county with a dozen freeze nights, that is often the better answer, and we’ll say so even when it is the smaller sale.