An 80 percent AFUE furnace sends a fifth of every heating dollar up the flue. Plenty of the ones still running in mid-century South Hills houses are twenty years old, and that math gets worse each winter. A homeowner who settles this in September, by picking a furnace company Pittsburgh PA neighbors have used, pays a planned price rather than an emergency one. Three warning signs and four questions, seven things total. None of them need a technician in your basement at six on a Sunday.
Warning Signs Your Furnace Is Near the End
Short cycling is the first tell. The furnace fires, runs ninety seconds, shuts down, then fires again a few minutes later. That points to a dirty flame sensor, a clogged filter, or a heat exchanger that no longer moves heat the way it was built to, and on a two-decade-old unit the third explanation is the usual culprit. Ignition misfire is the second sign. That delayed whump when the burners finally catch belongs in a phone call, not on a list of things to watch. The third sign is a gas bill climbing month over month while nobody touches the thermostat. A cracked heat exchanger can leak carbon monoxide into living space. Keep a working CO alarm on every floor, and if one sounds, get everyone outside and call 911 from the yard. The EPA advises anyone who suspects carbon monoxide poisoning to reach fresh air, shut off combustion appliances, leave, and go to an emergency room. Hundreds of people die every year from malfunctioning fuel-burning appliances.
Questions to Ask Every Furnace Installer
Price is the least interesting number on a furnace quote. Sizing, venting, and what happens when the new unit stumbles in year three matter more, and a rushed December estimate skips all three. Ask these four in writing, then watch how quickly the replies come back.
- What size did you calculate for this house, and did you run a full load calculation to get there? A good answer names a BTU figure and how it was reached.
- Is the efficiency rating you quoted the certified rating for this exact furnace and coil pairing? A good answer offers the certified reference number without being pushed.
- Who pulls the permit and schedules the municipal inspection, you or me?
- What does the labor warranty cover in year two, and who answers the phone at nine on a January night?
A quote that will not put a load calculation in writing is a guess wearing letterhead. Sizing is where the money hides. An oversized furnace short cycles from the day it is commissioned and chews through its own ignition parts, which is the failure we see most often on replacements done in a hurry. Check an efficiency claim yourself in five minutes with the AHRI Directory of Certified Product Performance, a free public lookup where the furnace and coil must appear together as a matched pair. Any furnace company Pittsburgh PA homeowners hire should hand over that reference number unprompted.
Lining Up a Company Before the First Freeze
Contractor calendars are the real constraint, not equipment stock. WSAW NewsChannel 7 reported in July 2026 that one heating and cooling shop fielded upwards of 70 service calls a day during that month’s heat wave, mostly failed capacitors and motors. Heating season does the same thing in reverse. A call placed in September buys a scheduled install date. A call placed in January buys a spot behind every no-heat emergency in the county. Say that gap costs a household $600 in space heaters, rush fees, and a hotel night. Honestly, closer to $900 once a frozen pipe joins the story.
Where the new furnace sits deserves a look while the basement is dry. Mechanical rooms in these older houses sit low, and one storm can swamp a whole city’s worth of them. Cincinnati Public Radio counted more than 900 sewer backup and basement flooding reports across the city after up to 5 inches of rain in a single event. Raw sewage carries bacteria, viruses, parasites and intestinal worms, so do not wade into a backed-up basement to check the equipment. Ask whether the replacement can sit on a raised platform.
Settle the three signs and the four questions now, while an installer can give your basement a full hour instead of twenty rushed minutes. Get the load calculation, the certified rating, the permit answer, and the financing terms on paper before October. A twenty-year-old furnace in a mid-century house is running on borrowed time. The only decision left is whether it gets replaced on your schedule or on its own.
