Fall Heating Checklist for North Texas Homes

Heating season in North Texas is short and lopsided. You might run the furnace ten nights in November and then not touch it again until a February front drops us into the teens. That long idle stretch is exactly why so many no-heat calls land on the same two or three nights every winter — everybody finds out at once that something quit back in April.

The fix is boring and effective: run through the system in October, while it is still 80 degrees out and nobody is uncomfortable. Here is the checklist we use, split into what you can do yourself and what genuinely needs a tech with a manometer and a combustion analyzer.

Run the heat before you need it

This is the single most useful thing on the list. Pick a cool morning, set the thermostat to heat, and push the setpoint five degrees above room temperature. Then stand there and pay attention for the full cycle.

You want to hear the inducer motor spin up, then the igniter click or glow, then the burners light, then the blower come on maybe thirty to sixty seconds later. If the sequence stalls anywhere — inducer runs but nothing lights, burners light and then shut down after a few seconds, blower never engages — you have found a real problem in October instead of at 11pm on a Tuesday in January.

You will also smell burning dust the first time. That is normal and should clear within fifteen or twenty minutes. A smell that is sharp, electrical, or oily, or one that persists past that first cycle, is not normal. Shut it down and have it looked at.

Change the filter, and check what size you actually need

A loaded filter starves the furnace of airflow. On a gas furnace that shows up as the high-limit switch tripping — the unit heats, gets too hot because air is not moving across the heat exchanger, and shuts the burners down. It cycles on and off, the house never quite warms up, and the heat exchanger takes abuse it was not designed for.

Put in a fresh filter and write the date on the edge of the frame with a marker. One-inch filters in DFW homes generally want changing every one to three months depending on pets and how much you run the system. Media cabinets with four- or five-inch filters go longer, often six months to a year.

One caution: a very high MERV filter in a system that was not designed for it can restrict airflow enough to cause the exact problem you were trying to avoid. If you upgraded filters and the system started short-cycling afterward, that is worth mentioning when you call.

Test the CO alarms — every one of them

Gas furnaces, gas water heaters, and gas ranges all produce carbon monoxide as a normal byproduct of combustion, and all of them rely on venting to carry it outside. A cracked heat exchanger, a blocked flue, or a bird nest in the vent turns that into an indoor problem. CO is odorless. Your nose is not a detector.

Press the test button on every alarm in the house. If it is battery-powered, put in new batteries regardless of what the test says. And check the manufacture date on the back — CO sensors wear out and most units are rated for five to ten years, after which the alarm is decoration.

Walk the outside of the house

Furnace venting terminates outside, and things happen to it over a long Texas summer. Look for the flue or PVC vent pipes and make sure nothing is blocking them — wasp nests, bird nests, shrubs that grew all summer, stacked patio furniture, a stray piece of insulation.

If you have a heat pump rather than a gas furnace, the outdoor unit is your heat source in winter too. Clear leaves and grass clippings away from the coil, give it a couple feet of breathing room on all sides, and never wrap or cover it. Covering a heat pump traps moisture and gives rodents somewhere warm to chew wiring.

Look at the vents and registers inside

Somebody closed a vent in a spare bedroom in July and never reopened it. Somebody else pushed a dresser over a floor register. Both are common and both make the rest of the house harder to heat while raising static pressure in the ductwork.

• Open every supply register, including in rooms you do not use.
• Move furniture and rugs off floor vents.
• Check that return grilles are not blocked by a couch or a bookshelf.
• Note any room that felt bad last winter — that is a duct or balance problem worth diagnosing now, not a thermostat problem.

Thermostat, batteries, and the schedule

Plenty of no-heat calls end at the thermostat. Replace the batteries if it takes them. Confirm the mode is actually on Heat and not Auto-with-a-weird-schedule left over from spring. If you have a smart thermostat, check that it reconnected to your wifi after whatever router reboot happened in June.

While you are in there: if the thermostat has an emergency heat or auxiliary setting and you have a heat pump, leave it alone. That mode runs expensive backup strips continuously and is meant for when the heat pump itself has failed, not for cold weather generally.

What a tech should check that you cannot

The homeowner list above catches the easy failures. A real fall tune-up goes after the things that are invisible from the hallway.

1. Inspect the heat exchanger for cracks or corrosion — the single most important safety check on a gas furnace.
2. Verify gas pressure at the manifold and confirm the burners are firing cleanly with a proper blue flame.
3. Run a combustion analysis and check CO in the flue, not just in the room.
4. Test safety controls: flame sensor, rollout switch, high limit, pressure switch.
5. Measure temperature rise across the furnace and compare it to the nameplate spec — this is how airflow problems get caught.
6. Check the flue draft and the condition of the vent connection.
7. Inspect the condensate drain on high-efficiency furnaces, which will clog and lock the unit out.
8. Tighten electrical connections and check amp draw on the blower motor.

That temperature rise measurement matters more than people expect. If a tech recommends replacing your system without ever measuring airflow or static pressure, that is a conversation worth pausing. Plenty of furnaces that get labeled undersized are actually fine equipment choking on restricted ductwork.

Do not forget the plumbing side

Fall is also when to get ahead of a hard freeze. Rockwall and the surrounding areas do not freeze often, but when we do it is usually sudden and it usually catches people with a hose still attached to the spigot. Disconnect hoses now, cover exterior faucets, and know where your main shutoff is and whether it actually turns.

The other item is your water heater. Our water is hard, and scale in the bottom of a tank makes it work harder right when demand goes up in winter. If it has not been flushed in over a year, fall is the time.

When to just call

• The furnace lights and then shuts off within a few seconds, repeatedly.
• You smell gas — leave the house and call from outside.
• A CO alarm has sounded, even once.
• You see soot, scorching, or rust streaks around the burner compartment or vent.
• The blower runs but the air coming out is cool.
• The unit is well past fifteen years old and something has started acting up.

We are family-owned and based right here in Rockwall, and we hold both a Texas Master Plumber license (TXM11693) and a Texas HVAC license (TACLB2360E), which means one crew can handle the furnace, the gas line, and the water heater in the same visit. Call (469) 338-5533 — we answer 24/7, and getting this handled in October costs less and hurts less than getting it handled in January.