Furnace Repair and No-Heat Service in Des Plaines

Furnace problems we are called out for

No heat at all is the call we hear most. The thermostat is asking for heat, the furnace either does nothing or starts and locks out, and the house begins losing temperature. Before a part is replaced we confirm power, the door switch, the filter, the gas supply and any safety lockout the control board has recorded, because a furnace that shuts itself down is usually protecting itself from a second problem.

Failure to start or ignite normally traces back to the ignition sequence: a cracked hot-surface igniter, a flame sensor coated in oxidation, a pressure switch that never closes because the inducer or the vent is restricted, or a control board that is not sending the signal. Each of those looks identical from the hallway and completely different at the unit.

A furnace blowing cold air often means the burners lit and then dropped out on a flame-sense fault, or the blower is running on a fan setting while the heat call has ended. Short cycling — heat for a few minutes, then off, then on again — commonly comes from a restricted filter, a dirty flame sensor, an overheating limit switch, or a furnace that was oversized for the house when it was installed.

Weak airflow, unusual noises and thermostat trouble round out the list. Rumbling on ignition, a metallic screech from the blower, booming at start-up or rattling panels each point at something specific: burner condition, motor bearings, delayed ignition or loose sheet metal. New noises are worth a call before they become the reason for a replacement.

How the diagnosis works

The technician reads the control board's fault history, then checks the sequence of operation in order — call for heat, inducer, pressure switch, ignition, flame proving, blower, limit. That sequence tells us where the system stops instead of leaving us guessing, and it means you are told what failed rather than what was swapped.

Combustion and safety checks are part of every heating repair visit. We look at the heat exchanger, the venting, the gas pressure and the condition of the burners. If we find a cracked heat exchanger or an unsafe venting arrangement, we show you what we found and explain the options rather than simply condemning the unit.

Igniters, flame sensors, pressure switches, capacitors, limit switches, blower motors, thermostats and control components are the parts that fail most often, and the common ones ride on the truck. That is why a large share of no-heat calls are finished on the first visit.

Repair or replace?

We will not talk you into equipment you do not need. As a rule of thumb, a furnace under roughly twelve years old with a single failed component is worth repairing. Once a unit is past fifteen years, has a cracked heat exchanger, or needs a repair that is a significant fraction of the cost of a new system, replacement usually becomes the better spend.

When it is close, we give you both numbers and let you decide. If you choose to move ahead, the details are on our furnace replacement and installation page.