Furnace Repair in O'Fallon, MO
Furnaces here run from October through April. If yours quits, tell us what it's doing and a licensed contractor who covers St. Charles County will get in touch.
Tell us about the job
It takes about a minute.
Seven months of work, in the cold
Your furnace runs from October through April here, about seven months of the year. On winter nights that average 25°F, it cycles on and off for hours at a stretch to hold the house steady. Every one of those starts puts wear on the igniter and the burner assembly.
Most homes in the area heat with gas, so that burner and igniter are doing the work night after night, all winter. When an igniter wears out, the furnace tries to start and fails, and the house goes cold with the blower still running. Add in the wind and winter storms this area sees most years, and a furnace that is already worn has less room to keep up when the power flickers or the temperature drops hard overnight.
- 7 months
- October through April, your furnace is on duty
- 25°F
- the average winter night it heats against
- 66%
- of homes here heat with gas, so most furnaces here burn gas
- 9 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
A new furnace would cut about $190 a year off heating for a typical St. Charles County home.
Estimates for a typical St. Charles 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 and the heat exchanger is sound.
Replacement makes sense when the heat exchanger is cracked or the furnace keeps needing parts.
- Why won't my furnace turn on?
- Start with the thermostat and the power. Check that it's set to heat and the temperature is above room temperature, then check the furnace switch and the breaker. If those are fine, the igniter may have failed, or a safety switch has shut the furnace down because of a clogged filter or a blocked vent. With lows around 25°F through the winter here, a furnace that won't start needs a contractor out soon rather than waiting it out.
- Why is my furnace blowing cold air?
- Most often the furnace is still warming up, and the blower runs before the air heats, so give it a few minutes. If cold air keeps coming, the igniter or flame sensor may be failing, so the burners never light and only the fan runs. A dirty filter can also choke off airflow enough that the air feels cool even when the furnace is heating normally.
- Why won't my furnace pilot light stay lit?
- A pilot light that won't stay lit usually points to a worn thermocouple, the small sensor that tells the gas valve the flame is burning. When it wears out, it reads no flame even when one is there and shuts the gas off. A draft blowing out the pilot or a dirty pilot orifice can cause the same thing, and a contractor can tell which one it is.