Once a year, and specifically in the fall. The timing is not arbitrary — it puts the inspection immediately before the season that will work the system hardest, while there is still time to fix what turns up.

Why Fall Rather Than Any Other Month

A furnace serviced in October gives you the whole winter with a system that has been verified. A furnace serviced in January gives you a system that has already been running unverified through the coldest weeks.

Hill Country freezes arrive abruptly. A warm October can turn into a hard freeze within days, and when it does, every heating call in the county lands within about eighteen hours. Booking service before that window is also how you avoid competing for appointments with everyone who waited.

What Happens During the Visit

The heart of it is combustion and safety.

The heat exchanger is inspected — the component that separates combustion gases from the air circulating through your house. Combustion is analysed at the flue, which measures what is actually coming out rather than inferring it. Gas manifold pressure is measured and adjusted to specification. Venting is checked for obstruction and secure connections.

Then the mechanical items: burners cleaned, igniter tested, flame sensor cleaned, pressure and limit switches verified, blower inspected and amp draw measured, and temperature rise measured against the rating plate.

That last number is the performance check. A furnace outside its specified temperature rise has an airflow or firing rate problem, and it will run that way indefinitely if nobody measures.

The Safety Case

If you only take one thing from this: the heat exchanger inspection is why annual service exists.

A cracked exchanger allows carbon monoxide into your supply air. It is colorless, odorless, and early symptoms resemble the flu — which is exactly what makes it dangerous.

Because our heating season is short, homeowners here are more tempted than most to skip fall service. The inspection is the reason not to, entirely independent of efficiency or reliability.

Reliability

The second benefit is not losing heat during a cold snap.

Igniters, flame sensors, pressure switches, and capacitors are wear items that give warning if someone is looking. A fouled flame sensor is a five-minute cleaning during a tune-up and a no-heat call in January if left alone.

There is a plumbing dimension here too. A Texas home without heat during a sustained freeze risks burst pipes, since supply lines often run through unconditioned attics. The water damage costs multiples of the furnace repair.

What About the Air Conditioner

Fall service covers heating. Cooling needs its own visit in spring, before the first sustained heat — which in the Hill Country matters more than the fall visit does, because cooling season here runs roughly seven months.

Two visits a year is the schedule: AC maintenance in spring, furnace maintenance in fall.

If you have a heat pump, the same equipment does both jobs year-round, and both visits are genuinely required rather than advisable.

Between Visits

Change the air filter — check monthly, replace when dirty. Restricted airflow is what causes limit trips and contributes to heat exchanger cracking, so this is not a minor task.

Keep the area around the furnace clear for combustion air, check the exterior vent after storms, and test your carbon monoxide detectors monthly.

Warranty Requirements

Most manufacturers require documented annual maintenance to keep coverage valid. A claim on a failed component with no service history is routinely denied, which is worth knowing on equipment still under warranty.

Keeping It on Schedule

The practical obstacle is remembering in fall when nothing is wrong. Our Care Club maintenance plan handles the scheduling, keeps the documentation, and adds priority dispatch for the week the weather turns.

We serve Fredericksburg, Kerrville, Boerne, Comfort, and the surrounding Hill Country. Contact 72 Degrees or call (830) 468-5316.