For more than a century, Deljo Heating & Cooling has been the name Evanston homeowners trust for reliable comfort solutions. Whether you need HVAC or plumbing solutions, our team delivers expert care backed by 5-star reviews and over 100 years of experience.
If you’re experiencing an HVAC or plumbing emergency, call us or click the button at the top of the page to schedule service online. Keep reading for an overview of our Evanston HVAC and plumbing services.
Plumbing Services in Evanston
No matter the issue, you can trust Deljo for prompt, affordable, and professional plumbing services. Our team provides comprehensive plumbing repair, from small leaks to major system issues.
If your hot water suddenly runs cold, we specialize in water heater repair, restoring comfort with fast and professional service. For clogged or slow drains, our expert drain cleaning clears buildup and keeps your plumbing flowing smoothly.
Air Conditioning Services in Evanston
Summers in Evanston demand a dependable cooling system. That’s why Deljo offers expert air conditioner repair to restore your comfort quickly when your AC breaks down. From refrigerant issues to electrical malfunctions, our licensed technicians handle every kind of AC issue. We also provide seasonal air conditioning maintenance and professional air conditioning installation to keep your home comfortable all summer long.
Heating Services in Evanston
When temperatures drop, Deljo is here to keep your family warm with expert heating services. If your furnace stops working or struggles to heat evenly, call us for reliable furnace repair. Our technicians provide thorough diagnostics and long-lasting repairs so you’re never left in the cold.
We also specialize in boiler repair and professional heating installation, ensuring your system runs safely and efficiently for years to come.
Why Choose Deljo Heating & Cooling in Evanston?
There are plenty of companies you could call when something goes wrong with your plumbing or HVAC. But Evanston families have been turning to Deljo for generations. The reasons why they do this include:
- We show up when it matters most. Burst pipes and broken furnaces don’t wait for a convenient time. That’s why we’re available 24/7 for emergency HVAC and plumbing services.
- We’ve been doing this for over 100 years. Over our century of operation, we’ve seen it all. We know how to get the job done right the first time.
- Our reputation speaks for itself. We’re proud of the thousands of 5-star reviews we’ve earned. They don’t come from flashy ads. They come from neighbors who were treated fairly and had their problems solved quickly.
- We make comfort affordable. Big repairs and replacements can be stressful. That’s why we offer flexible financing options that take the sting out of an unexpected bill.
- We take care of our customers. With our Gold Star Program, customers get priority scheduling, regular maintenance, and extra perks. It’s our way of saying thank you for trusting us with your home.
At Deljo, it’s simple: we treat you the way we’d want to be treated. That’s been our approach for more than a century, and it’s why so many Evanston families keep our number handy.
Call Your Trusted Evanston Plumbing & HVAC Experts
Ready to take care of that plumbing issue or finally get your heating and cooling running the way it should? Deljo Heating & Cooling is here to help. Give us a call or request an instant quote today and see why Evanston has trusted us for over 100 years.
Recent Jobs and Reviews in Evanston, IL
Evanston, IL at a glance
Deljo Heating, Cooling & Plumbing has completed 20 jobs in Evanston, IL between February 2026 and March 2026.
The most recent job was on March 14, 2026.
Job Locations and Reviews
Responded to emergency call regarding boiler not heating after previous parts replacement. Identified error message indicating insufficient circulation flow rate (below 8 GPM), causing temperature limitation to 140°F. Inspected and adjusted Grundfos circulation pump and associated control valves to restore proper flow rate, resolving the heating issue.
Replaced failed ignitor (under part warranty) and degraded flame sensor on Navien heating system. Accessed internal components by removing front panel to perform the repair. Proper operation of ignition system and flame detection verified after installation.
Responded to call for no hot water in customer's Navien boiler system. Diagnosed faulty control board as the source of the issue. Temporary repair not possible; replacement board has been ordered and will be installed upon arrival.
Completed installation of a new Carrier furnace with integrated thermostat and humidifier according to specified scope of work. Performed comprehensive system testing including differential pressure measurements with manometer, confirming proper operation at 1.50" WC. Installation included complete PVC venting system with appropriate condensate drainage to ensure optimal system performance and efficiency.
Performed routine maintenance on HVAC system per Agreement terms. Inspected Honeywell thermostat (set at 79°F with heat active) and examined furnace interior components including wiring connections, control board, and blower assembly. All systems operating within normal parameters.
Responded to callback for boiler not functioning despite recent repairs. Diagnostic testing revealed faulty control board circuit with compromised connections. Replaced damaged wiring harness and recalibrated digital interface on hydronic system to restore proper operation of circulator pump and control functions.
Responded to no-heat service call for 15-year-old furnace that was not turning on. Performed diagnostic inspection of system, including thermostat and control board wiring connections. Identified and resolved electrical issue, restoring proper furnace operation and confirming system functionality before completing service.
Completed installation of two neutralizers and replaced 3/4" relief valve on tankless water heater. Added vinyl drain to chimney drain and performed descaling service on tankless unit to remove mineral buildup and restore optimal performance.
Returned to complete gas valve changeout on existing system as previously quoted. Installed new Honeywell gas valve and verified proper operation. Checked system performance parameters with diagnostic tool and confirmed heating function through thermostat operation.
Performed annual maintenance on 1-year-old 89% efficiency gas furnace located in laundry room. Inspected thermostat functionality (confirming 72° reading and proper system response) and examined interior components including blower motor, wiring connections, and gas valve assembly. Verified proper flame sensor operation as indicated by blue illumination in burner section.
Performed scheduled commercial maintenance service on 2 rooftop units. Changed filters (16x25x2 and 24x24x1) and inspected interior components. Noted significant rust and corrosion on metal surfaces of one unit, particularly on the frame. Inspected mounting hardware and brackets while wearing protective gear. Completed all work as outlined in maintenance agreement.
Performed scheduled maintenance on CC 1 Boiler system, humidifier, and tankless water heater per agreement. Inspected all plumbing connections including copper pipes, PVC components, and control valves for proper operation. Verified functionality of control panel with indicator lights and checked integrity of insulated piping and electrical connections.
Responded to service call for boiler displaying error code E-012 and not turning on. Diagnosed thermostat settings and verified proper heat call signal at 67°F setpoint with current room temperature at 64°F. Inspected boiler control panel and reset system using red reset button, which cleared the error code and restored normal operation.
Performed scheduled maintenance agreement service on two furnaces and two humidifiers. Inspected and cleaned blower assembly components. Removed and examined air filters, noting one filter with minor staining; filters not included in agreement as specified (#35 -- 20x25x5 not included GS).
Diagnosed Carrier furnace issue causing cold air output and short cycling. Performed electrical testing with multimeter showing 15.24 amp draw. Identified and replaced two damaged air filters that were bending due to excessive pressure differential, which was restricting airflow and causing system inefficiency.
Responded to no-heat call for system less than 10 years old. Discovered humidifier leaking which had tripped the safety device and shut down the furnace. Inspected and replaced the clogged humidifier filter pad which showed significant mineral buildup, and adjusted the humidistat from near-off position to appropriate setting for current outside temperature.
Returned to complete scheduled blower wheel cleaning service on the HVAC system. Accessed the furnace interior, removed the blower assembly, thoroughly cleaned the wheel to remove accumulated dust and debris, then reinstalled and verified proper operation of all components.
Performed fall heating tune-up on residential system, including inspection and maintenance of Aprilaire whole-home humidifier and furnace unit. Checked electrical connections, heat exchanger integrity, and control board functionality, ensuring optimal operation for the heating season.
Performed complete check and clean on furnace and water heater per maintenance agreement. Inspected gas combustion chamber showing proper blue flame pattern and clean ignition. Examined plumbing connections and valves on water supply system, noting normal mineral buildup but no leaks or immediate concerns. Media replacement not included in this service.
Conducted assessment of 13-year-old HVAC system including Carrier furnace and outdoor AC unit, evaluating repair vs. replacement options. Inspection revealed aging components with purple-marked PVC ventilation connections and documented current filter specifications. System has easy access for replacement with outdoor unit positioned on prepared mulch bed with stone paver surround. Completed evaluation before customer's 1PM departure deadline.
