Furnace Repair in Crystal Lake, IL
Furnaces here run from October through May. If yours quits, tell us what it's doing and a licensed contractor who covers McHenry County will get in touch.
Tell us about the job
It takes about a minute.
Eight months of heat wears a furnace down
Crystal Lake needs heat from October through May, eight months of the year. On nights that average 17°F through the winter, the furnace is not just running, it's cycling on and off for hours at a stretch to hold the house at temperature. Every one of those cycles asks the igniter to light the burner again, and igniters are built to do that only so many times before they crack or stop glowing hot enough to catch the gas.
McHenry County has logged 18 winter storms and 140 damaging wind events over the past ten years. When the power drops and comes back, most furnaces need their control board to reset and their igniter to fire again, and that is often where the trouble shows up first.
- 8 months
- October through May, your furnace is on duty
- 17°F
- the average winter night it heats against
- 85%
- of homes here heat with gas, so most furnaces here burn gas
- 18 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
A new furnace would cut about $150 a year off heating for a typical McHenry County home.
Estimates for a typical McHenry County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Illinois 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.
In Illinois, HVAC licensing for homes is left to the cities and towns.
That means there's no state board testing furnace contractors or keeping a record on them. Whatever oversight exists comes from the town or county the house sits in, and McHenry County covers a lot of small municipalities, each free to set its own rule or set none at all. Some require a local license before anyone touches a furnace. Others leave it open.
With 85% of McHenry County homes heating with gas, the part of this job that matters most is the gas connection itself. A bad connection or a vent that is not sealed right is the dangerous part of a furnace repair, gas leaking or exhaust going where it should not. Whether anyone checks that work here depends on the municipality, not on a state license, because Illinois does not issue one.
Source: Illinois General Assembly
- Why won't my furnace turn on?
- Start with the thermostat. Make sure it's set to heat and the temperature is set above room temperature, then check the batteries if it has a screen that looks dim or blank. If the thermostat looks fine, check your breaker panel, since a tripped breaker will shut the furnace down completely. Furnaces also have a switch that looks like a light switch near the unit itself, often on the wall next to it, and it needs to be in the on position. If all of that checks out and the furnace still won't start, the igniter or the control board may have failed, and that calls for a contractor to look at it.
- Why is my furnace blowing cold air?
- Most of the time this means the furnace is running the fan without the burners lit. Check the thermostat fan setting. If it's set to on instead of auto, the blower runs constantly and pushes cold air between heating cycles, so switching it to auto usually solves it. If the fan is already set to auto and you're still getting cold air, the igniter or flame sensor may be failing, which stops the burners from lighting even though the blower still runs. A dirty filter can also cause the furnace to shut its burners off early as a safety measure while the fan keeps blowing. If none of that fixes it, a contractor will need to check the ignition system directly.
- Why won't my furnace pilot light stay lit?
- This is almost always the thermocouple, a small sensor that sits in the pilot flame and tells the gas valve it's safe to stay open. When it wears out or sits slightly out of position, it can't sense the flame properly and the gas valve shuts off, even though the pilot lit just fine a moment ago. A draft can also blow the pilot out, so check whether anything nearby is pushing air toward it. If you relight the pilot and it goes out again within a minute or two, the thermocouple is the likely cause and a contractor will need to replace it.