Exceptional climate control does more than keep you comfortable in extreme weather. It also reduces household humidity, minimizes mold, and improves air quality. That’s why A+ Derr is more than just an HVAC company. We strive to improve your quality of life in three core areas: comfort, budget, and energy efficiency. We repair all makes and models of HVAC systems, whether you need to dial down the heat in summer or up in winter. We offer 24/7 emergency repairs and a wallet-friendly maintenance plan to make life a little easier. We install some of the industry’s finest systems as a Lennox Premier Dealer.Take control of your comfort by calling A+ Derr’s Mount Carmel team at (877) 914-1764 or schedule service online.
Expert Heating
We work with a wide range of HVAC brands and models. Our expertise extends to heat pumps, furnaces, ductless mini-splits, and more, so we can help you track down the perfect option for your pocket. Our services include:
- Heating repair: We’ll diagnose your symptoms correctly and ensure your repair lasts.
- Heating installation and replacements: HVAC systems have a life span of 10 to 25 years. If your system has reached the end of its life and requires frequent repairs, we offer a 100% satisfaction guarantee for the year after your installation.
- Heating maintenance: Your system can only perform optimally if serviced at least once a year. Our maintenance plan makes annual services easier to budget for and schedule.
Arrange a heating service with A+ Derr in Mount Carmel by calling us at (877) 914-1764.
Dependable Cooling
We have decades of experience behind us, so we’ve dealt with every air conditioning problem imaginable. We use the latest best practices and high-quality components. We offer:Â
- AC repair: If your AC is leaking, buzzing, or displaying other worrying symptoms, we’ll execute a flawless repair. If your system breaks down during an unforgiving heat wave, our 24/7 emergency team will take care of it promptly.
- AC installation and replacement: We’re a Lennox Premier Dealer, so we can bring you industry-leading equipment and install it precisely as the manufacturer intended.
- AC maintenance: An annual service will keep your system’s energy efficiency in top shape and extend its life span.
Indoor Air Quality Solutions
You spend most of your life indoors. Air quality can have a dramatic impact on your health. We maintain, repair, and replace humidifiers, dehumidifiers, and air purifiers. We also offer a fastidious duct cleaning service to keep your air allergen-free and your HVAC system functional.Take your indoor air quality to new heights by contacting the Mount Carmel A+ Derr team at (877) 914-1764.
Why Choose A+ Derr?
A+ Derr has been a family-owned business for four generations, so we truly understand the importance of old-fashioned values. We strive to offer the finest solutions and products on the market. Our 100% satisfaction guarantee assures you of absolute security. We always offer prompt, trustworthy service and 24-hour emergency repairs. As an A+ BBB-accredited company with a five-star review average, we’ve proven our mettle, and that’s why our clients rate us so highly. Call A+ Derr’s Mount Carmel team at (877) 914-1764 for expert HVAC assistance, or schedule an appointment online.
FAQs
Is switching to a ductless air conditioner right for me?
If your architecture makes ducts impossible, a mini-split is the perfect option for full zone control. A mini-split can also improve your air quality if you suffer from allergies. You won’t experience accumulated dust and dander with no ductwork hidden from view.
Why won't my furnace turn on?
Dirty filters can reduce airflow, rendering your furnace useless, but your fuel source might also be responsible. You might have a faulty gas supply if your pilot light has gone out. Blower motors and ignition switches are equally common.
Recent Jobs and Reviews in Mount Carmel, IL
Job Locations and Reviews
Completed Platinum Level preventive maintenance on a 3-year-old residential split system air conditioning unit. Serviced outdoor condenser unit and indoor air handler, replaced 16x25x5 air filter, performed comprehensive system inspection including electrical connections, refrigerant levels, and condensate drainage, and verified proper operation of all components. Unit tested and left in optimal working condition per manufacturer specifications.
Completed annual Platinum Level maintenance on single-system residential HVAC unit located in attic space. Performed comprehensive inspection of air handler, ductwork, and thermostat system per manufacturer specifications. Verified proper operation of smart thermostat settings and confirmed all system components functioning within normal parameters.
Responded to service call for heating and cooling system with recurring communication errors causing complete system shutdown, particularly during rain events. Upon inspection, confirmed customer suspicion of moisture intrusion through damaged wire shielding affecting communication between furnace control board and AC unit. Traced wiring harness, identified compromised section with exposed conductors allowing water penetration into low-voltage communication circuit. Replaced damaged communication wire section with properly rated thermostat cable, ensuring proper shielding and weatherproofing at all connection points. Verified all wire terminations at control board and outdoor unit, tested system communication protocol, and confirmed furnace and AC operation without error codes. System now operating normally with restored communication integrity.
Installed 100-amp automatic transfer switch for generator system on exterior wall with stone facade. Mounted equipment on concrete pad adjacent to building, ran appropriate conduit along foundation, and connected necessary wiring to integrate with existing electrical service.
Completed site assessment for whole home generator installation. Documented existing electrical service panel mounted outdoors in wooded area showing signs of weathering with vegetation growth nearby. Evaluated utility pole installation with meter connection to determine appropriate generator sizing and placement options for future whole home backup power system.
Completed planned annual maintenance on Platinum Level HVAC system. Investigated customer-reported acetone-like odor during AC operation. Inspected system components for refrigerant leaks and verified proper operation. System is functioning correctly with 20x25x5 filter in place.
Conducted on-site assessment for home standby Generac generator installation. Examined existing 200-amp electrical panel showing significant weathering and corrosion. Evaluated property for appropriate generator placement and noted propane as intended fuel source.
Conducted 6-month planned maintenance service including replacement of 16x25x5 PureAir filter. Performed diagnostic testing of circuit board components with all connections secure and functioning properly. Temperature differential readings measured at 12.7°F, confirming system is operating within specifications.
Completed annual maintenance on NSSU system with 16x25x5 filter. Performed inspection of control board and electrical components using voltage tester to verify proper operation. System was installed 11/4/25 and this was the 1st visit of the maintenance cycle; customer declined renewal at this time.
Completed installation of a 26kW Generac generator system, which included routing conduit through basement joists and securing proper connections to the main electrical panel. Inspected structural elements to ensure proper placement and clearance for the generator installation.
Conducted a comprehensive generator installation estimate, evaluating the existing electrical infrastructure including dual breaker panels and available utility connections. Assessment confirmed property has a standard breaker panel setup with natural gas availability, making it suitable for generator installation with proper electrical integration.
Successfully installed a complete HVAC system featuring a furnace unit with comprehensive PVC ventilation network and drainage components. System includes a digital multi-zone climate control panel with customizable airflow settings for different areas of the residence. All equipment was properly mounted, connected, and tested for optimal performance.
Conducted assessment for a complete HVAC system replacement at a large residential property (2201+ sq.ft.) with existing unit located in crawlspace. Took detailed measurements of the installation area and examined current ductwork configuration. Customer requires both heating and cooling capabilities with natural gas as the energy source. Recommended Lennox horizontal gas furnace and AC system appropriate for the property size.
Completed 6-month planned maintenance service on HVAC system. Replaced 16x25x5 air filter. Performed gas pressure test with readings of 3.26-3.30 inWC and temperature check showing 64°F, confirming system is operating within manufacturer specifications.
Responded to customer-reported water leak. Inspection of the crawl space revealed extensive root intrusion surrounding the plumbing system, with roots infiltrating areas around PVC drainage pipes. Identified this root intrusion as the likely cause of the water leak reported by the water department. Documented conditions with photos showing the severity of root encroachment on plumbing infrastructure.
Successfully installed a 2-ton tankless water heater system in utility alcove. Unit was properly mounted on wall with all necessary water, gas, and electrical connections completed according to manufacturer specifications. System was tested and is functioning normally with proper temperature regulation.
Conducted on-site assessment for a complete HVAC system replacement. Documented current installation location and surrounding area with photos. Customer requested quote for new system options, focusing on energy-efficient "green" solutions. Will prepare detailed estimate with multiple replacement options including equipment specifications and efficiency ratings.
Responded to service call for water in crawl space. Upon inspection, discovered crawl space contained significant accumulation of nesting materials and debris around plumbing infrastructure. Evaluated moisture issues and assessed potential need for sump pump installation to address ongoing water intrusion.
Responded to no heat complaint for a 6-7 year old system that was experiencing delayed ignition, loud banging noise during operation, and failure to maintain consistent heating cycles. Diagnostic inspection revealed gas pressure irregularities causing improper combustion. Adjusted gas valve settings, cleaned flame sensor and burner assembly to eliminate ignition delay and combustion issues. System now ignites properly with normal operation and consistent heat output.
Successfully installed a complete GREEN3T HVAC system with model number 18 99 DS. The installation included proper connection of the furnace unit with PVC venting and integration with the existing water heater system. All components were properly mounted, connected, and tested for optimal performance.
