The Houston checklist, drain first
Houston runs about 3,280 cooling degree days a year in climate zone 2A, with dew points in the 70s from May to September. The evaporator coil pulls gallons of water a day out of that air, and the drain line that carries it away is the most common failure point in the metro. A tune-up that does not treat it has skipped the one thing that matters:
- Condensate line flushed and treated. Algaecide tablets in the pan or a flush through the cleanout; the line proven to flow at the outdoor stub.
- Float switch tested. If there is not one on the primary pan, this is the visit to add it. It is the difference between a dark thermostat and a wet ceiling.
- Secondary pan and line checked on attic air handlers — Katy, Cypress, Pearland and every 2000s two-story.
- Refrigerant charge verified by superheat and subcooling, not a gauge glance. Houston systems run seven months; a marginal charge in April is an empty one in August.
- Evaporator coil inspected, cleaned if accessible. Humid bypass air grows biofilm on the coil face.
- Condenser coil cleaned — Gulf grime and cottonwood; worse east of downtown where the air is salty.
- Capacitor tested against rating; replaced if more than 10% low. Heat kills them and the season is long.
- Static pressure and temperature split recorded — the numbers that show whether the ducts are choking the system.
When to book it in Houston
The calendar is driven by one fact: from June to August every contractor in Harris County is on emergency calls and tune-up slots do not exist.
| Month | Visit | Why then |
|---|---|---|
| March–April | Cooling tune-up | Before the first 85°F humid week. Drain treated, charge set, capacitor checked while parts and techs are available. |
| June–August | None scheduled | Filter monthly. Pour a cup of vinegar down the drain cleanout monthly. Keep the condenser clear. |
| October | Heating check | Before the first front. The furnace has sat eight months; see below. |
| Every 30–60 days | Filter | Houston dust and humidity load a 1-inch filter faster than the 90-day label suggests. |
Where in Houston
Contractors in the network cover Harris County and the counties that grew into it: Katy and the Energy Corridor west; Cypress, Spring and The Woodlands north; Sugar Land and Missouri City in Fort Bend; Pearland and League City south; Pasadena and Baytown east; and the loop neighborhoods — the Heights, Montrose, Bellaire, Meyerland. Maintenance needs track the housing: attic air handlers in the 2000s suburbs need the secondary pan and line checked every visit; closet units in 1960s Bellaire and Spring Branch ranches need the long horizontal drain run sloped and flushed; anything east toward the bay needs the condenser coil rinsed against salt.
The October heating check
Houston has about 1,220 heating degree days a year, and the furnace's whole season is a few weeks around each Arctic front. A heating check in October is cheap insurance against the no-heat call on the night the front arrives. On a gas furnace it should include:
- Burner cleaning and flame inspection; flame sensor cleaned and ignitor resistance checked.
- Heat exchanger inspection — combustion analysis on anything over ten years, and every Houston furnace has sat in a 140°F attic all summer.
- Condensate trap on high-efficiency units cleared — the number one Houston furnace lockout.
- Inducer and blower amp draws, capacitor test; limit, rollout and pressure switch operation; flue and venting; carbon monoxide reading at the supply.
On a heat pump: heat-mode operation, defrost cycle, reversing valve, and the auxiliary strips staged and measured — a heat pump running silently on strips is the Houston winter bill surprise.
Attic air handlers: the secondary pan
Nearly every Houston home built since the late 1990s — Katy, Cypress, Pearland, League City, The Woodlands — puts the air handler in the attic, over a bedroom or a hallway. The primary drain runs to a plumbing stack; the secondary pan under the unit has its own line to an eave outside, and a float switch in that pan is the last line before a ceiling. Every spring visit in one of those homes should include: the primary line flushed, the secondary pan dry and its line clear, the float switch tripped by hand to prove it cuts the system, and the pan checked for rust-through, because a rusted pan drains onto the drywall. If water ever drips from a pipe over a window, that is the secondary line telling you the primary is blocked — call before the ceiling stains.
CenterPoint's tune-up offer
CenterPoint Energy Houston Electric runs an A/C tune-up program for residential customers in its service area: an independent certified technician assesses the system and makes efficiency improvements. It applies to a central AC or heat pump that is at least a year old and operational, single-family only (apartments excluded). CenterPoint also pays incentives, starting at $200, on a replacement at 15.2 SEER2 or better through a participating contractor — relevant when the tune-up finds a compressor on its way out. Current terms: CenterPoint Energy efficiency programs.
Licensing, and the permit you do not need
Maintenance needs no permit anywhere in Harris County; only a replacement does, through the Houston Permitting Center inside the city. The tech who opens the refrigerant circuit to check the charge must hold a license from the TDLR Air Conditioning and Refrigeration program; a "tune-up" by an unlicensed handyman cannot legally include the one measurement that matters.
What maintenance costs in Houston
Houston labor is at the low end of the five metros and plan prices reflect it. What to expect, and what to demand for the money:
- $95–$220
- Standalone spring AC tune-up. Should include the drain treatment, charge by subcooling, capacitor test and recorded numbers. A $59 "inspection" is a sales visit.
- $110–$240
- Standalone fall heating check with combustion analysis.
- $160–$320 / yr
- Two-visit plan, spring and fall. Worth it on a system 5+ years old in this climate if it lists what is measured, not just what is inspected.
- $300–$550 / yr
- Premium plan with priority scheduling in July and a repair discount. Worth it past ten years, or if a mid-summer outage is not survivable in your house.
- $40–$120
- Float switch, installed during a tune-up. Cheapest insurance on this page.
If the tune-up finds an ignitor about to go or a heat exchanger past its life, the Houston furnace repair page has the repair costs. The full tune-up checklist and plan comparison for any metro are on the maintenance page. Seasonal outlook: National Weather Service Houston/Galveston.