When your heater or air conditioner stops working, it can be disruptive to your daily life. We understand how important it is to have a comfortable home and will respond quickly to fix the issue. Our technicians are highly trained and experienced, so you can rely on Deljo Heating and Cooling to get the job done right the first time.
Our company has been providing top-notch HVAC services to Chicagoland for over 100 years, and our customer satisfaction focus has earned us our stellar reputation. We believe good business is built on relationships, so earning your trust is our priority.
Deljo Heating and Cooling is committed to delivering premier HVAC maintenance, repair, and installation services with every visit for every customer.
HVAC Maintenance
The best way to prolong the lifespan of your heating and cooling system is to schedule regular maintenance. Another advantage of keeping up with maintenance is that your system will run more effectively and efficiently, keeping your home comfortable and your energy bill low.
Ideally, maintenance should be done every spring and fall to ensure peak performance during seasons with extreme temperatures.
Heating & Cooling Repair
From heat pumps and ductless systems to boilers and traditional AC units, Deljo Heating and Cooling has the experience and skill to repair any HVAC system. Our specially trained technicians will diagnose and repair your heater or air conditioner promptly and professionally.
HVAC Installation
All heating and cooling systems eventually break down and wear out, even with the most meticulous care. When your HVAC system needs to be replaced, you can count on Deljo heating and cooling to provide the highest caliber of service when replacing or upgrading your system. If you need a new installation, our team can make professional recommendations best suited to your home, needs, and budget.
Emergency HVAC Services
When we say we care about our customers, we mean it – we are only ever a phone call away. Regardless of day or time, when your heater or air conditioner stops working and you need us, we will be there. During extreme weather conditions, a broken HVAC system can put people and pets at risk for illness, count on Deljo Heating and Cooling.
Trusted HVAC in Des Plaines
For over a century our customers have put their trust in Deljo Heating and Cooling for all their heating and air conditioning needs. We invite you to experience the Deljo Difference when your HVAC system needs service in Des Plaines. We promise to meet or exceed your expectations or your money back, so schedule an appointment today.
Recent Jobs and Reviews in Des Plaines, IL
Des Plaines, IL at a glance
Deljo Heating, Cooling & Plumbing has completed 10 jobs in Des Plaines, IL between February 2026 and April 2026.
The most recent job was on April 13, 2026.
Job Locations and Reviews
Conducted on-site assessment for complete HVAC system replacement including furnace and air conditioning unit. Evaluated existing outdoor condensing unit currently positioned on concrete pad with lattice skirting and inspected accessible plumbing infrastructure. Documented equipment specifications, measured installation clearances, and photographed current system configuration to prepare comprehensive replacement estimate for new heating and cooling equipment.
Conducted on-site evaluation of non-functioning boiler system over 20 years old for replacement assessment. Inspected existing combination boiler unit, associated plumbing components including brass pressure regulator valve and aged supply piping showing mineral deposits and discoloration. Documented current HVAC infrastructure including insulated ductwork and air handler components in utility space. Provided comprehensive estimate for boiler replacement and discussed options for concurrent air conditioning unit replacement to address both heating and cooling system upgrades.
Responded to no-heat call for aging furnace (10+ years old). Inspection revealed significant dust accumulation on blower wheel affecting airflow and operation. Cleaned and serviced blower assembly, inspected burner components showing rust and wear, and restored system functionality. Unit operational upon departure.
Responded to service call back for gas shut-off issue following recent valve replacement. Performed diagnostic testing on control components using digital multimeter and inspected gas line connections. Verified proper operation of furnace system after restoring gas supply, confirming all electrical connections were secure and functioning correctly.
Conducted full system estimate for replacement of aging 17-year-old HVAC equipment with new 2-stage furnace and air conditioner. Inspection revealed existing installation in basement utility area with complex PVC drainage/ventilation network and current furnace showing signs of age-related wear. Photographs documented current system configuration and installation constraints for proper sizing and placement of recommended replacement equipment.
Returned to property to replace failed pilot assembly on water heater as scheduled. Removed old assembly with corroded fittings and installed new pilot assembly with proper connections to ensure reliable ignition. Tested system operation with diagnostic probe to verify proper flame sensing and confirmed water heater is now functioning correctly.
Diagnosed zone control issue in customer's boiler system. Upon inspection, found aging wiring connections at the zone valve and control board that were causing intermittent operation. Repaired wiring connections and tested all zones for proper functionality, confirming system is now operating correctly.
Returned to residence to replace faulty gas valve in boiler system as scheduled. Disconnected existing gas line, removed deteriorated valve assembly from heat exchanger, and installed new OEM gas valve. Performed operational test after installation, confirming proper ignition sequence and normal flame pattern across copper heat exchanger tubes.
Responded to callback for boiler pilot light failure issue, same as previous day's service call. Upon inspection, found faulty thermocouple requiring replacement. Tested gas valve, cleaned pilot assembly, and verified proper operation of ignition system. Unit now functioning correctly with stable pilot flame.
Responded to call for boiler service as pilot light would not stay lit. Inspected the McClain boiler system including pressure gauge, temperature readings, and copper connections showing oxidation. Completed comprehensive on-the-water service to resolve the pilot light issue, ensuring proper system function and safe operation.
