When the cooling quits in Dallas, ask what the system has been carrying

The failures we see every season

The upstairs surrenders by supper, and the downstairs never knows The defining Dallas complaint, and it arrives in August, not June. The house kept its cool through the ordinary morning, and then the day stacked its heat into the roof, the attic climbed past the point where insulation matters, and by supper the upstairs thermostat is losing ground it will not win back until well after dark, while the downstairs, shaded and low, holds without effort. Three stories produce it, and the hours separate them. One version: the upstairs system has been losing a step a season, a tired compressor valve, a coil matted with dust and oak pollen, and the stacked August week is simply the first exam hard enough to grade it. Another: a slow refrigerant leak leaves the upstairs unit cooling at part strength from morning on, and it falls behind at the very hour its load peaks. And the third is the sizing story, the one the far north tells oftenest: the system never held this upstairs in August, because it was sized for the plan's square footage rather than for the glass, the roof, and the west exposure the plan actually got built with. A system that held the same rooms five summers ago and cannot now is losing something. One that never held them is telling the older story, and the older story has honest answers too.

The registers blow warm, and the house keeps gaining Air moves through the house in quantity and none of it arrives cold, while the thermostat climbs the wrong way through the afternoon. Start outside. What the outdoor box is doing while that warm air pours splits the case in half. Quiet out there, with the indoor half running, points to a start component that has quit, the capacitor or the contactor, leaving the compressor with no orders to run on, and on this crew it also raises the power question Felix asks first: what does the circuit look like at the disconnect, because a share of silent outdoor units are electrical stories wearing a mechanical costume. Noise out there, a running unit that still cannot cool, moves the hunt into the sealed circuit: refrigerant escaped through a slow leak, or a compressor worn past its strength by a decade of stacked summers. Stand by the outdoor unit for half a minute and listen before you pick up the phone. Marta's first question is what you heard.

The hail came through, and the unit has not cooled right since North Texas writes a failure the milder markets never meet, and the northeast suburbs keep its date. In April 2016 a hailstorm crossed Wylie and the streets around it with stones big enough to make the national news, and it folded the fins on outdoor coils across whole neighborhoods in one evening, the way a boot folds grass. A coil that cannot breathe cannot shed heat: the system runs longer, cools less, and spends its compressor doing it. Dents in the cabinet are the visible part. The costly part is the fin field underneath, and the question of whether it combs back or has folded for good. The storm is years back now, and its chapter is still open: units that were combed and units that were never looked at have been paying different electric bills ever since. A system that cooled fine before a storm and labors after one is telling a storm story, not a wear story, and the two get priced differently. Tell Marta a storm hit your street when you call, whenever it hit. In hail country, a storm carries a date, and the date belongs in the diagnosis.

A zone quit answering, and the rest of the house is fine The far-north failure the older markets never meet, because older houses do not have zones. In the big zoned plans across Plano, Frisco, and McKinney, one thermostat governs a wing through a damper in the ductwork, and when the damper's motor tires, or its control board stops asking, or the thermostat itself goes quiet, that wing drifts warm while the rest of the house holds its number and the equipment sounds innocent. The system is not failing; it is not being told. The hunt runs through the low-voltage half of the house, controls, dampers, sensors, and that is Felix's native country: circuit by circuit, in order, with the silent one named. Report the zone when you call: which wing, and whether its thermostat lights up at all. A dark thermostat and a lit one are different patients with the same warm bedroom.

Ice on the lines, in the middle of a Dallas summer Ice on a refrigerant line surprises Dallas owners most, because it arrives in the season of 100-degree days, but the physics is the same here as anywhere: the coil surface drops below freezing and stores the house's moisture as frost instead of sending it down the drain. Two roads lead there. Starve a coil of air, with a clogged filter or a mat of dust, and its surface drops below freezing; starve it of refrigerant instead, with a charge gone low, and it gets there from the other direction. The humid end of summer feeds the process, loading the air with more water than the dry weeks hold, in exactly the weeks the equipment runs longest. Both roads end at the same instruction: off, thawed, then diagnosed. Keep a frozen system running and it cools nothing at all, while every drop of melt it has stored waits to land somewhere when the ice lets go, and under an attic unit that somewhere is a ceiling. Note the timing when you call. Ice discovered at noon argues one case; ice discovered at bedtime argues the other.

The duct leak that keeps coming back at the same joint Between the equipment and the far bedroom, the cold is leaking away or was never made at full strength to begin with, and in Dallas there is one suspect the other markets do not have at the same strength: the ground itself. The black clay under most of this side of the metroplex swells when it is wet and shrinks when it is dry, the slab moves by fractions across the seasons, and duct connections fastened to the slab move with it, working loose by degrees at the same stressed joints. A joint sealed twice that opens a third time is not a sealing failure; it is a soil report. Past the soil, suspicion runs to a blower losing speed by degrees, a charge drifted until the system cools the short runs and starves the long ones, or, in the big northern houses, the second system that serves the far wing quietly quitting while the working system carries a house and a half. Finding which of those it is comes first, because each one prices differently, and the soil story prices once instead of annually.