J&J heating and cooling | Local HVAC Repair in Chicago, IL

A furnace that won't ignite is a common and urgent issue during our winters. First, check that your thermostat is set to 'heat' and that the gas valve is on. If it still fails, the problem could be a faulty thermocouple, a dirty flame sensor, or a draft blowing out the pilot. For your safety and to prevent further damage, it's best to call a professional. J&J's technicians are experts in diagnosing and repairing furnace ignition failures to get your heat back on reliably.

Improper installation is a leading cause of high energy bills, uneven temperatures, and frequent breakdowns in our climate. A system that's the wrong size or poorly sealed will struggle during extreme heat and cold. At J&J, we perform precise load calculations to ensure your new furnace or AC is perfectly sized for your home's layout and insulation. Our meticulous installation process focuses on airflow, sealing, and calibration, which maximizes efficiency, extends system life, and keeps your home comfortable year-round.

While changing a filter is a simple task, certain signs always require an expert. These include strange noises (banging, screeching), the furnace constantly cycling on and off (short-cycling), a yellow burner flame instead of blue, or a persistent burning smell. In Chicago's winter, ignoring these signs can lead to a complete breakdown or a safety hazard. Our technicians can accurately diagnose the root cause—whether it's a failing heat exchanger, blower motor issue, or gas valve problem—and provide a lasting, safe repair.