Heating & Cooling

Heat rises, second floors sit under hot attics, and a single downstairs thermostat cannot see upstairs temperatures. Contributing problems include undersized or leaky supply ducts, poor attic insulation, an oversized AC that satisfies the thermostat before upstairs cools, and inadequate upstairs return air. From Airflow Balancing to Zoning to Mini Splits Fixes range from airflow balancing and duct sealing to zoning systems with a thermostat per floor, or a ductless mini split serving the problem...

Watch for: age over 15–20 years, repair bills approaching a third of replacement cost, rising gas bills, uneven heating, short cycling, rust or corrosion, and any heat exchanger concern — a cracked heat exchanger is a carbon monoxide risk and usually ends the repair-or-replace debate. The Repair-Times-Age Rule Multiply the repair estimate by the furnace’s age; if it exceeds the cost of a new unit, replacement usually wins. Modern furnaces reach up to 98% AFUE, so Chicagoland homes replacing a 20...

Central air conditioners in Illinois typically last 12–17 years. Our climate means fewer runtime hours than the Sun Belt, but humid summers, freeze-thaw cycles, and cottonwood-clogged condensers take their toll — and neglected maintenance shortens life dramatically. Maintenance Is the Difference Between 12 and 17 The biggest factor in reaching the long end of that range is annual professional maintenance: clean coils, correct refrigerant charge, clear condensate drains, tight electrical connecti...

The only correct answer comes from a Manual J load calculation — a room-by-room analysis of square footage, insulation, windows, air leakage, and orientation. Square-footage rules of thumb produce oversized systems in most Chicagoland homes. Why Oversizing Is the Most Expensive Mistake An oversized furnace short cycles, heats unevenly, wears out faster, and costs more up front and every month after. A properly sized system runs longer, gentler cycles that hold temperature evenly. Any quality quo...

An AC that runs constantly without reaching setpoint usually has low refrigerant from a leak, a dirty condenser or evaporator coil, a clogged filter strangling airflow, leaky ductwork dumping cooled air into the attic, an aging compressor, or was undersized from day one. Diagnose Fast — Continuous Running Is Expensive Check the filter first, then coils, refrigerant charge, and duct integrity. Nonstop running punishes both your electric bill and the compressor, so professional diagnosis quickly b...

Call for repair when you notice unusual noises (grinding, banging, squealing), weak airflow, warm air in cooling mode or cool air in heating mode, frequent on-off cycling, unexplained utility bill spikes, moisture or ice on equipment, or burning and musty smells from vents. Small Symptoms Become Big Failures Most major breakdowns telegraph themselves weeks in advance as minor symptoms. A failing capacitor stresses the motor it serves; a refrigerant leak slowly cooks the compressor. Addressing sy...

The clearest signals: utility bills creeping up year over year with similar weather, longer run times to reach the same temperature, rooms that used to be comfortable turning hot or cold, excess humidity in summer, and a system that never seems to shut off during peak season. Measure It, Then Fix It Efficiency loss usually traces to dirty coils, low refrigerant charge, clogged filters, duct leakage, or aging components — all measurable and most fixable in a single maintenance visit. A tune-up ty...

Call immediately for safety issues: burning smells, suspected gas or carbon monoxide, ice on equipment, or total loss of heat in winter. Call soon for warning signs: strange noises, weak airflow, short cycling, rising bills, or uneven rooms. Call seasonally for maintenance — spring for cooling, fall for heating. Sooner Is Almost Always Cheaper HVAC problems compound: a $30 filter ignored becomes a frozen coil; a weak capacitor becomes a dead compressor. The best time to call is when something fi...

Yes — when your heat fails on a January night or your AC dies in a July heat wave, All Set HVAC provides prompt emergency service throughout Arlington Heights and the Chicago Northwest Suburbs. Call (847) 807-6100 and a licensed local technician will get your system safely back online. Maintenance Club Members Jump the Line When extreme weather hits, every HVAC phone in Chicagoland rings at once. All Set Maintenance Club members receive priority service — and because maintained systems rarely fa...