The first cold Monday of the season, the office phone tells you what the weekend did. A small Fort Smith business opens up, somebody flips the thermostat from cool to heat, and the dining room or the sales floor stays cold. For a business, heating trouble on a weekday morning means unhappy customers and staff in coats, and most of it can be caught on a fall visit before the first freeze.
What follows is a composite of the rooftop heat checks we run every fall around Fort Smith, the way a typical visit goes. It isn’t one particular customer, but every step in it is real.
Getting on the Roof
Most small commercial buildings in Fort Smith, from strip-center storefronts to offices and restaurants, are heated and cooled by packaged rooftop units: one cabinet on the roof holding the cooling side, a gas heat section, and the blower, with ducts dropping straight down into the space. Before anyone climbs up, we ask the manager what they’ve noticed. Is one side of the building colder? Any smells when the heat first came on? Does the thermostat have a schedule, and does anyone know who set it?
Then it’s up the ladder or through the roof hatch. First look is the unit itself: panels in place, no water pooling, no fresh damage from summer hail, the gas line and its shutoff intact, and the condensate drain line clear.
Airflow First
Rooftop units live hard lives. The filters get looked at first, and on a lot of fall visits they haven’t been changed since spring. A clogged filter on the heat side causes the same problem it does in a house: the heat section runs too hot, a safety limit shuts the burners off, and the space never warms up.
Next is the blower. On older belt-drive units the belt wears, glazes, and slips, so a unit can run with the blower barely moving air. We check belt tension and wear, pulley alignment, and bearings, and look at the blower wheel for buildup. A restaurant unit pulling kitchen air can coat a wheel in grease faster than you’d think.
The Gas Heat Section
This is the heart of a fall visit. We fire the heat and watch it light: the inducer starts, the igniter glows or sparks, the burners light evenly, and the flame sensor proves the flame. We check gas pressure and look at the burners for rust, debris, or insects that moved in over the summer, which is common in a unit that sat idle since March.
Then the heat exchanger. We inspect it for cracks, rust-through, and signs of overheating, because it’s the part that keeps combustion gases out of the air going into the building. We also check that the flue and the vent hood are clear.
🛠 What we do: on every rooftop heat check we measure the temperature rise across the heat section, test the high-limit and rollout safeties, clean the flame sensor, and confirm the unit cycles off when the thermostat is satisfied. Anything we find goes on a short list with photos, so the owner or manager can see exactly what we saw on the roof without having to climb up there.
Controls and the Thermostat
A lot of “no heat” calls on commercial buildings turn out to be controls. A programmable thermostat still set to a summer schedule, set to cool-only, or locked by someone who’s no longer with the business. Many rooftop units also have an economizer, a damper that brings in outside air to cool for free in mild weather. When it sticks open in winter, it pulls cold air into the building all day. We check that the damper moves and closes the way it should.
Before We Leave
We walk the space with the manager, check air coming out of the registers on the far end of the building, and go over what we found. Small items like a belt, filters, or a cleaned sensor get handled that day when the parts are on the truck. Bigger items get a written quote before any work starts. If the unit is near the end of its life, we’ll say so honestly and let the owner plan for it on their schedule, not in the middle of a January cold snap.
If something does fail outside business hours, we’ll come out. After-hours work is billed at an overtime rate, and we’ll quote it before we roll.
Do I need a separate heat check if my rooftop unit was serviced for summer?
Yes. A spring visit focuses on cooling. The gas heat section has its own checks, and fall is the time to do them.
Do I need to change filters more than twice a year?
Many businesses do, especially restaurants and dusty shops. We can set a filter schedule to match your building.
Commercial Heating You Can Count On in Fort Smith
Clark HVAC is a family-owned, licensed and insured heating and cooling company, and we service and install commercial rooftop units in Fort Smith and across the River Valley. We’ll check your units before the cold sets in, explain what we find in plain English, and give you the price before any work starts.
📞 Call Now: 918-839-3734
Straight answers. Fair pricing. Clean work.