If you smell gas, leave the house and call 911 and your gas utility before anything else.
Centerville is small enough to drive across in a few minutes and varied enough that two houses a mile apart can have different heating problems. The neighborhoods on the valley floor and the ones climbing the bench toward the mountains are not in the same environment: the bench is colder, windier and gets weather first. Most of the housing here went up between the 1960s and the 1990s, which puts a large share of the original and first-replacement furnaces at or past the age where failure stops being a surprise. The calls we get reflect that mix — no heat on the coldest night of the year, and systems that still run but should not be counted on for another winter.
Davis County gets strong east winds down off the Wasatch, and the bench neighborhoods take the worst of it. For a furnace, wind matters in one specific place: the vent. A high-efficiency furnace vents through a plastic pipe out a sidewall, and a sidewall termination facing into a wind event can see enough pressure to interfere with the draft. Older mid-efficiency equipment venting into a chimney has the opposite problem, where a downdraft can spill combustion products back toward the appliance.
Both show up the same way to a homeowner: the furnace starts, runs briefly, shuts down, and tries again. That cycling is usually a pressure switch or a flame sensor doing its job rather than failing, and the fault is outside the furnace. Replacing parts inside the cabinet will not fix a vent termination in the wrong place or a chimney that is no longer drafting.
So a Centerville diagnosis on a windy-day failure should include a look at where the vent comes out, what is around it, and which direction it faces. If a contractor wants to replace a board before anyone has been outside to look at the termination, that is worth questioning.
A house built in 1972 has probably had one furnace replacement, and that replacement is now itself old. A house built in 1994 may still be on its original equipment. Either way, a large part of Centerville’s furnace population is in the last stretch of its service life at the same time, which is why the honest conversation here is often about timing rather than about a single part.
The questions that decide repair versus replace are specific. Is the heat exchanger intact. How many times has this unit been repaired in the last three seasons. Is the blower motor original. Is the thing running because it is healthy, or because someone keeps nursing it. A cracked heat exchanger is not a repair item: it is a combustion safety problem and the appliance should be shut down, not patched.
Where replacement is the answer, the sizing conversation matters more than the brand. A furnace sized for the house as it is now — after whatever insulation, windows and additions have happened since it was built — is a different number from the one on the old nameplate, and oversizing causes short cycling and uneven heat rather than more comfort.
Most no-heat calls are not catastrophic. Before anything else, there are a few things a homeowner can check that account for a surprising share of them: the thermostat is calling for heat and has working batteries, the furnace switch on the wall or the side of the unit has not been turned off, the breaker has not tripped, and the filter is not so loaded that the system is overheating and shutting itself down on a limit switch.
A badly clogged filter is the single most common cause of a furnace that runs and then quits. If the filter has not been changed this season, that is the first thing to look at, and it costs nothing to rule out.
What is not a do-it-yourself item: anything involving the gas valve, the burners, the heat exchanger or the venting. If you smell gas, leave and call 911 and the gas utility from outside. If a carbon monoxide alarm sounds, the same applies. Those are not diagnostic puzzles to work through in the basement.
Short cycling like that is usually a safety switch doing its job rather than failing. The two common causes are a filter so loaded that the furnace overheats and trips a limit switch, and a venting or draft problem that trips the pressure switch. On the bench in Centerville, east wind against a sidewall vent is a real possibility, so the vent termination is worth looking at outside before anything in the cabinet is replaced.
No. A cracked heat exchanger is the barrier between combustion gases and the air circulating through your house, and it is not a patch item. The correct response is to shut the appliance down and either replace the heat exchanger if the unit is new enough to warrant it, or replace the furnace. If you want a second opinion before spending that money, that is reasonable — but do not keep running it while you decide.
That depends on things worth checking rather than on age alone: whether the heat exchanger is sound, how many repairs it has needed in the last few seasons, and whether the blower and the controls are original. A unit that has been reliable and tests clean can reasonably be run another season with monitoring. One that has needed three service calls is telling you something, and planned replacement is cheaper and warmer than emergency replacement.
Describe what the furnace is doing and we'll match you with a licensed contractor who can act on it.
Get a Furnace Contractor OutA short description is enough — we'll follow up to confirm the details and get someone scheduled.
