HVAC Repair in Florissant, MO
Homes here need heat from October through April and cooling from May through September. If your system quits, tell us what it's doing and a licensed contractor who covers St. Louis County will get in touch.
Tell us about the job
It takes about a minute.
Florissant asks a lot of your system, in both directions
Your furnace runs from October through April here, and on the nights that drop to 26°F, it cycles on and off for hours to keep up. Most homes in Florissant heat with gas, so that means the burner lighting again and again, all night, every winter. The igniter and the flame sensor take that wear. When one fails, the furnace either won't fire or shuts down partway through the cycle, and the house goes cold.
Then summer flips the load the other way. Afternoons averaging 87°F from May through September push the air conditioner's compressor hard, for months at a stretch. On top of that, nearly one in five Missouri households lost power for at least a day in 2024, and a storm knocking out power during a heat wave or a cold snap is exactly when a weak system gives out for good.
- 7 months
- October through April, your system heats
- 5 months
- May through September, it cools
- 26°F
- the average winter night it heats against
- 87°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
A new furnace and air conditioner would cut about $210 a year off heating and cooling for a typical St. Louis County home.
Estimates for a typical St. Louis County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Missouri fuel prices and NOAA climate normals. Your home will differ.
Repair makes sense when one part has failed.
Replacement makes sense when the furnace's heat exchanger is cracked, the air conditioner's compressor has failed, or repairs keep coming.
- Why is my heat not working?
- Start with the thermostat and the power to the furnace. If the display is dark, check the breaker and any switch that looks like a light switch near the unit, since that shuts the furnace off too. Gas furnaces will not fire if the pilot or igniter fails, or if a safety switch trips because the filter is clogged and airflow is blocked. With winter nights here averaging 26°F, a furnace that will not stay lit needs a contractor out quickly rather than repeated restarts.
- Why is my system running but not cooling the house?
- The fan running does not mean the system is actually cooling. A clogged filter or a dirty outdoor unit can choke off airflow enough that the air coming out barely feels cool. Low refrigerant from a leak will do the same thing, and that needs a contractor with gauges to confirm. Check the filter first, since that is the one thing you can rule out yourself before calling anyone.
- What can I check before calling for HVAC repair?
- Check the thermostat batteries and settings first, since a dead battery or a mode set wrong looks exactly like a broken system. Check the filter next and replace it if it is gray or clogged. Check the breaker panel and any disconnect switch near the indoor or outdoor unit. If any of those are fine and the system still will not run, a contractor will need to look at it.