Any time your air conditioner or heater stops working, life is interrupted. Not only is it uncomfortable to be too hot or too cold in your home, but it can also be dangerous. It’s important to have someone you know you can trust to promptly repair your HVAC in Oak Park, IL.
Deljo Heating, Cooling & Plumbing has been servicing the greater Chicago area for over a decade and has earned the trust of countless homeowners. We are proud of the reputation we have built, and we intend to continue the service we are known for.
HVAC Maintenance Services
Regular maintenance of your heating and cooling system is essential for continued efficiency and longevity. We recommend biannual service during spring and fall to ensure your HVAC system will work reliably throughout extreme high and low temperatures. Our HVAC technicians will inspect, test, and clean your system, replacing worn parts. We will make sure everything is working efficiently before leaving your home.
HVAC Repair Services
Whether you need AC repair, furnace repair, or anything in between, our technicians have the experience and knowledge to diagnose and repair any heating or cooling system. We arrive promptly for your appointment, remain professional and respectful of your time and home, and fully address all questions and concerns you may have.
If for some reason part of your HVAC system is beyond repair, we will discuss your needs and together decide how to proceed.
Air Conditioning and Furnace Installation
Dejo Heating and Cooling can install any type of boiler, furnace, heat pump, AC unit, or dual system you may need. If you are ready to upgrade but are unsure what system is best for your home, we would be happy to discuss your needs and budget and make a professional recommendation you feel confident with.
Our team works quickly to ensure your timely return to comfort. Our goal is your satisfaction, and we take that very seriously.
HVAC Services in Oak Park, IL
During the century Deljo Heating, Cooling & Plumbing has served the greater Chicago area, we have developed a high standard of excellence that’s promised to every customer, every time we visit.
We truly care about our neighbors, and we want you to be comfortable and safe in your home. That’s why we also offer emergency repair service, no matter what time of day or night. Experience the Deljo Difference yourself, and rely on us for all your HVAC service needs.
Recent Jobs and Reviews in Oak Park, IL
Oak Park, IL at a glance
Deljo Heating, Cooling & Plumbing has completed 20 jobs in Oak Park, IL between September 2026 and October 2026.
The most recent job was on October 15, 2026.
Deljo Heating, Cooling & Plumbing has completed 116 jobs in Oak Park, IL in the last 12 months.
Job Locations and Reviews
Replaced the furnace, condenser, evaporator coil, and thermostat as a complete system changeout. Evacuated the system to 206 microns to verify a dry, leak-free circuit before releasing refrigerant, and configured the new communicating thermostat with the line set parameters (3/8" liquid line, 3/4" vapor line, 15 ft length) to ensure proper system setup and operation.
Performed scheduled maintenance on two gas furnaces, two humidifiers, and one water heater, including inspection of the furnace cabinets, condensate and venting PVC, ductwork, and the blower assembly. Verified safe, proper operation of all equipment and confirmed the 16x25x4 media filter is due for replacement (filter supplied separately).
Replaced failed contactors on both outdoor condensing units to restore proper compressor operation. Installed TRADE PRO hard start capacitors (compressor savers) rated for 2.5-5 ton systems on Unit 1 and Unit 2 to reduce startup amperage draw and extend compressor lifespan. Verified proper electrical connections, tested all components with diagnostic equipment, and confirmed both Carrier units are operating within manufacturer specifications.
Completed comprehensive cooling check and tune-up on single furnace system per maintenance agreement. Verified system operation with supply air temperature reading of 128.1°F and measured electrical draw of 76.7 amps, confirming equipment is functioning within normal operating parameters.
Completed comprehensive fall heating tune-up and safety inspection on 90% efficiency boiler system. Performed thorough examination of heat exchanger for cracks and deterioration, tested all safety controls for proper operation, and verified exhaust vent functionality. Conducted home carbon monoxide testing to ensure safe operation. Cleaned burner and pilot assemblies, inspected blower motor and wheel for debris accumulation, and cycled all operating controls to verify proper function. Inspected natural gas lines for detectable leaks, examined line voltage switches and wiring for safety compliance, and assessed system for presence of dirt, mold, or mildew. Tested indoor relative humidity levels. Thermostat displaying proper temperature reading of 70°F with clear digital display. Observed aged copper plumbing components with corrosion and patina present on piping. All safety systems operational and unit ready for heating season.
Completed comprehensive boiler maintenance and safety inspection as part of annual agreement service. Inspected primary heat exchanger, burner assembly, and pressure vessel components; noted significant corrosion present on boiler grate structure requiring monitoring for future replacement consideration. Verified proper operation of expansion tank, checked all piping connections, and confirmed system pressures within manufacturer specifications.
Completed comprehensive tune-up and maintenance on 16-year-old boiler system. Performed combustion analysis and leak detection testing using calibrated diagnostic equipment at gas valve assembly and burner section. Cleaned burner tubes and surrounding work area, removing debris to ensure optimal system performance and safety.
Performed comprehensive boiler maintenance and inspection as part of annual service agreement. Inspected and photographed Taco 007-F5-17 cartridge circulator pump, verified proper operation and connections to copper piping system. Conducted thorough examination of gas burner assembly, heat exchanger components, and ignition system to ensure safe and efficient operation for the heating season.
Conducted comprehensive assessment of existing HVAC system in basement utility area for full system replacement estimate. Customer expressed interest in upgrading to Carrier Performance series equipment for both heating and cooling components. Evaluated current furnace installation, ductwork configuration, and air conditioning requirements. Documented existing galvanized metal duct system with vertical runs and rectangular transitions, noting dust accumulation on surfaces. Assessed basement mechanical room layout including concrete floor conditions, exposed framing, and existing utility connections. Photographed current furnace unit with front grille panel, supply ductwork extending from unit top, and ceiling-mounted distribution system secured with metal straps. Reviewed electrical wiring paths, structural clearances, and access points for equipment replacement. Prepared specifications for Carrier Performance system installation including furnace and air conditioning components matche
Completed furnace replacement for 16-year-old unit that was shut down and no longer operational. The existing furnace had easy access for removal and installation. Documented existing ductwork measurements showing 13-inch diameter supply plenum, and photographed exterior HVAC equipment including dual air conditioning condensers positioned on gravel pad with proper refrigerant line sets and drainage components connected to the building exterior.
Performed comprehensive maintenance on residential furnace and humidifier system as part of preventative maintenance agreement. Conducted thorough inspection of heating unit, verified proper operation of all components, and took combustion analysis readings using calibrated digital instruments which showed system operating within normal parameters at 759 reading. Replaced 20x25x1 air filter with customer-supplied unit to maintain proper airflow and system efficiency. Inspected ductwork connections, interior compartment, and all accessible components for wear, dust accumulation, and proper function. System tested and confirmed operational with no issues identified.
Responded to no heat call for furnace intermittently shutting off. Upon inspection, diagnosed faulty inducer motor causing unit to cycle on safety. Inspected blower motor, electrical connections, and control board for additional issues. Documented equipment condition with photos showing internal components including motor assembly, wiring harnesses, and control relays for service records and future reference.
Completed comprehensive maintenance inspection on Lennox furnace system and associated water heater as part of annual maintenance agreement. Verified proper operation of all furnace components, inspected heat exchanger, checked burner assembly, and confirmed adequate combustion air supply. Examined PVC venting system for proper installation and clearances. Inspected water heater connections and plumbing fittings, verified proper operation of safety devices, and documented equipment condition through photographic records. All systems found to be operating within manufacturer specifications.
Conducted comprehensive assessment of 18+ year old furnace system experiencing inadequate cooling performance. Documented existing basement-installed HVAC unit with dark gray cabinet, PVC venting, and associated ductwork configuration. Performed detailed measurements of equipment dimensions and clearances using precision measuring tools. Evaluated complete system including furnace cabinet, supply and return ductwork, venting components, and installation environment. Photographed equipment nameplate data, unit positioning, ductwork connections, and mechanical room layout to develop accurate replacement specifications for full system estimate.
Responded to no cooling call on residential HVAC system less than 10 years old. Performed diagnostic inspection of air handler unit located in attic space, checked refrigerant lines, ductwork connections, and electrical components. System evaluated and customer provided with pricing options for necessary repairs.
Replaced defective evaporator coil with faulty TXV under manufacturer warranty. Evacuated system, installed new coil assembly, pulled proper vacuum to 500 microns, charged system to manufacturer specifications, and verified proper operation with all pressures and temperatures within normal range.
Completed full HVAC system replacement including furnace, condenser unit, evaporator coil, and programmable thermostat. New outdoor condenser unit installed on concrete pad with proper electrical connections and refrigerant lines routed through foundation. Digital thermostat installed and programmed to manufacturer specifications, displaying proper operation at 42 degrees setpoint during system testing.
Responded to service call for air conditioning system not turning on. Upon investigation, confirmed issue was related to Ecobee thermostat communication. Communicated with customer via text message to coordinate appointment scheduling and service details.
Responded to no cooling complaint caused by wet switch safety shutoff. Upon inspection, found excessive condensate accumulation in air handler drain pan triggering the float switch. Cleared condensate drain line obstruction, verified proper drainage, tested system operation, and confirmed unit cycling normally with wet switch reset.
Responded to callback for intermittent indoor fan operation. Performed diagnostic evaluation of blower motor and control board assembly, taking measurements and documentation of clearances and component positioning within the air handler. Verified system operation and documented findings with photographic evidence of the mechanical components and piping configuration for service records.
