
When something goes wrong at home—a leaking pipe, a faulty light switch, or an air conditioner that just can’t keep up, it can throw your whole day off. At A+ Derr Heating, Cooling, Plumbing, & Electrical, we’re more than just service pros, we’re neighbors who understand what it means to keep your home running. Our team provides dependable heating, cooling, plumbing, and electrical services in Mount Vernon backed by real experience, licensed professionals, and a commitment to treating you right, from the first call to the final cleanup. Call our team today at 833-232-4328 or connect with us online for more information.Â
Mount Vernon Plumbing Services for Better Functionality
It might start with a slow drip under the sink or a little water pooling where it shouldn’t—but before you know it, you’re dealing with water damage and rising stress. That’s why our local Mount Vernon plumbers respond quickly, work efficiently, and always treat your home with care. We’re here to fix the problem and make things right—without the mess or the worry.
- Drain Cleaning & Sewer Services: When your sinks or tubs stop draining like they should, we’re there with fast solutions. Our team clears out stubborn clogs and inspects your sewer lines to make sure everything flows the way it should.
- Sump Pump Services: A flooded basement can be a homeowner’s nightmare. We install and maintain reliable sump pumps that keep your lower level dry and protected.
- Water Heater Installation & Repair: Nobody wants to start their morning with an ice-cold shower. Whether it’s a traditional tank or a tankless system, we’ll get your hot water flowing again—fast.
- Garbage Disposal Repair & Replacement: A jammed or broken disposal can bring your kitchen to a halt. We repair or replace units with minimal disruption, so you can get back to your routine.
- Pipe Leak Detection: Not all plumbing problems are visible. We use smart technology to track down leaks inside walls and under floors before they become costly repairs.
- Fixture Installation: Upgrading your bathroom or kitchen? We install faucets, toilets, and other fixtures with care, precision, and an eye for clean design.
- General Plumbing Repairs: Whether it’s a mystery drip, a running toilet, or something bigger, our team handles plumbing issues of every kind—quickly, cleanly, and with no guesswork.
Complete Air Conditioning Services in Mount Vernon, IN
If you’ve spent a summer in Mount Vernon, you know the heat and humidity aren’t just uncomfortable—they’re relentless. A working air conditioner isn’t a luxury here—it’s survival. That’s why our Mount Vernon cooling services are built for real-world Indiana weather, keeping your home cool, your energy bills low, and your peace of mind intact.
- AC Repair Services: Warm air? Weak airflow? Loud noises? Our repair techs find and fix the problem fast.
- New AC Installation: Whether it’s a replacement or a new build, we install energy-efficient air conditioners that meet your needs and your budget.
- Mini-Split System Installation: No ducts? No problem. These compact units offer zoned comfort with powerful efficiency.
- Seasonal AC Maintenance: Prevent breakdowns, lower your bills, and extend the life of your system with a quick annual tune-up.
Reliable Heating Services for Mount Vernon Homes

Winter in Mount Vernon has a way of creeping in fast—and when it does, there’s no comfort like a warm, cozy home. If your heating system is struggling to keep up or suddenly goes out, we’re the team you can count on. From quick fixes to total system upgrades, our heating services are built to handle Indiana’s toughest cold snaps with comfort and confidence.
- Furnace Installation & Maintenance: When your old furnace is costing you comfort and cash, it’s time for a smart upgrade. We install and maintain systems designed to keep up with unpredictable Indiana winters.
- Boiler Repair & Replacement: Radiator heat has its perks—until your boiler acts up. We repair and install boiler systems in Mount Vernon to ensure even, efficient heating throughout your home.
- Heat Pump Services: Want one system that can do it all? Our heat pumps offer reliable heating in the winter and energy-saving cooling in the summer.
- Geothermal Heating Systems: Tap into stable underground temperatures with geothermal systems that reduce your carbon footprint and your utility bills.
- Emergency Heating Repairs in Mount Vernon: Heating problems don’t follow a schedule. That’s why our team is ready 24/7 to get the heat back on—fast and fuss-free.
Safe Electrical Services in Mount Vernon
From simple switch swaps to full rewires, our licensed electricians are here to make your home safer, smarter, and better powered for everyday life. Whether you’re upgrading for convenience or fixing a frustrating issue, we handle it with expert precision and a neighborly touch.
- Electrical Panel Upgrades: Still relying on an outdated breaker box? We install modern panels that power today’s tech-savvy homes safely and reliably.
- Outlet & Switch Installations: From USB charging ports to sleek smart dimmers, we upgrade your switches and outlets to match how you live today.
- Service Upgrades: Whether you’re adding new appliances or simply need more reliable power, our service upgrades ensure your home’s electrical system can keep up with modern life.
- Equipment Repair: From faulty outlets to flickering lights and worn-out switches, we diagnose and repair aging or damaged electrical components to keep your home safe and running smoothly.
- Light Commercial Services: Have a small business in Mount Vernon? We offer light commercial electrical work—from lighting and outlets to panel upgrades—to help keep your operation efficient, functional, and compliant.
- Whole-Home Surge Protection: One lightning strike or power spike can fry your electronics. Our surge systems shield your entire home from unexpected voltage surges.
- Interior & Exterior Lighting: Brighten your kitchen, highlight your landscaping, or increase nighttime safety with professionally installed lighting that looks as good as it works.
- Backup Generators: When the grid goes down, stay up and running. We install standby generators that kick in automatically and power your essentials.
- EV Charger Installation: Tired of slow charging from a basic outlet? We install fast, reliable EV chargers so you can power up your vehicle right from your driveway.
Clean Indoor Air Quality Services in Mount Vernon
Temperature is only half the story when it comes to comfort at home. If the air you’re breathing is stale, dusty, or too dry, it can take a toll on your health and energy. That’s why we offer indoor air quality solutions that go beyond basic HVAC—making your home feel fresher, healthier, and easier to live in every day.
- Whole-Home Air Purifiers: Tired of breathing in dust, pollen, and who-knows-what else? Our air purifiers tackle airborne irritants and help you breathe easier in every room.
- Humidity Control Solutions: Whether your home feels dry enough to shock you or muggy enough to match the outdoors, we install humidifiers and dehumidifiers that bring your indoor climate back to balance.
- Duct Cleaning & Sealing: Over time, air ducts can turn into dust highways. We clean them out and seal leaks to boost efficiency, improve air quality, and help your system work smarter—not harder.
- Filter Replacements & Upgrades: Not all air filters are created equal. We help you find the best fit for your system and swap them out to keep air flowing clean and free of allergens.
Book Your HVAC, Plumbing, or Electrical Service in Mount Vernon, IN
Need fast, reliable service for your home systems? A+ Derr Heating, Cooling, Plumbing, & Electrical proudly serves Mount Vernon, IN with high-quality heating, cooling, plumbing, and electrical solutions. Call 833-232-4328 today to schedule your service and experience why local homeowners trust us for peace of mind year-round.
Recent Jobs and Reviews in Mount Vernon, IN
Mount Vernon, IN at a glance
A+ Derr Heating & Cooling has completed 20 jobs in Mount Vernon, IN between March 2026 and April 2026.
The most recent job was on April 10, 2026.
Job Locations and Reviews
# HVAC Install - Complete System Successfully completed installation of a complete 3-ton HVAC system with 18 SEER rating and 99% AFUE gas furnace. Installed Lennox outdoor condensing unit on concrete pad against exterior brick wall with proper clearances and secure mounting. Unit model SLFP99DF070XV36BK-01 installed indoors with all manufacturer labeling and safety notices properly affixed. Connected electrical service with external disconnect box mounted to building exterior. Verified proper refrigerant charge, tested all electrical connections, and confirmed system operation at design specifications. All equipment installed per manufacturer guidelines and local building codes.
Completed Platinum Level planned maintenance on single HVAC system. Performed comprehensive system inspection including temperature differential measurements at supply and return vents, recording 67.5°F at the indoor coil and 58.3°F at the supply register. Checked all mechanical and electrical components, verified proper airflow, and confirmed system operation within manufacturer specifications.
Completed plumbing estimate for installation of gas line to supply furnace in attic space. Assessed existing HVAC infrastructure, ductwork, and insulation to determine optimal routing for new gas supply line. Documented current conditions including corroded metal components and insulation placement to plan safe gas line installation pathway that complies with code requirements.
Conducted on-site assessment of 16-year-old residential air conditioning system to provide replacement estimate. Inspected existing outdoor condensing unit positioned on concrete pad adjacent to building exterior, noting current refrigerant line configuration, electrical disconnect placement, and PVC condensate drainage routing. Evaluated indoor HVAC system layout using downflow configuration diagram to determine proper sizing and clearance requirements for new equipment installation, including furnace, evaporator coil, and base specifications. Documented existing installation conditions through photographic records for accurate equipment selection and proposal preparation.
Performed follow-up service call to address continuous fan operation issue on outdoor HVAC condensing unit. Conducted system inspection and documented equipment condition with site photographs showing unit positioned on concrete pad against exterior wall with electrical conduit and refrigerant line connections visible. Addressed outstanding work items from previous installation to resolve fan control malfunction.
Completed annual second visit platinum level maintenance on 6-year-old residential HVAC system with Aspen R-410A evaporator coil and furnace assembly. Performed comprehensive inspection of all system components, verified proper operation of TXV-equipped evaporator unit, and documented equipment condition with photographic records. Replaced 20x20x5 air filter and confirmed all safety labels and manufacturer specifications remain legible and intact for future service reference.
Installed a 50-gallon tall electric water heater in utility closet with complete copper piping configuration, including blue expansion tank mounted above unit with proper connections and red-handled isolation valve. All components professionally installed and tested to manufacturer specifications with clean workmanship throughout the confined space installation.
Completed full HVAC system installation including a 4-ton, 18 SEER air conditioning unit paired with a 97% efficiency furnace. The installation included subfloor plenum configuration with proper ductwork integration. The outdoor condenser unit was positioned on a composite equipment pad with adequate clearance from the structure, electrical disconnect installed on exterior wall with appropriate conduit routing, and all refrigerant lines properly insulated and secured.
Completed electrical installation and commissioning of Generac automatic transfer switch for standby generator system. Verified proper electrical connections between utility service, transfer switch, and generator unit, ensured all conduit runs and wiring meet code requirements, and documented final installation with photographs for service records.
Completed Platinum Level maintenance on single HVAC system during first scheduled visit of the service year. Inspected and serviced mechanical equipment including red-mounted unit with ventilation component installed between wall studs in basement utility area. Noted significant moisture damage and water staining on concrete floor surface near equipment location, documented conditions with photographs for customer awareness and future monitoring.
Responded to water leak complaint in basement area beneath furnace unit. Upon arrival, discovered significant water accumulation under 4-year-old HVAC system with condensate pump installed. Inspected condensate pump assembly, drain lines, and overflow safety switch for proper operation and potential failure points. Identified source of water discharge causing moisture damage to surrounding basement flooring. Documented extensive water damage to parquet hardwood flooring showing discoloration, warping, and moisture penetration across large area near equipment location. Cleared condensate drainage system and verified pump cycling and discharge functionality. Advised homeowner of findings and recommended monitoring for additional water accumulation to ensure proper system operation moving forward.
Performed comprehensive system evaluation on 21-year-old HVAC equipment in 2,300 sq ft bilevel home experiencing complete loss of cooling due to refrigerant depletion. Documented existing air conditioning and furnace conditions, photographed electrical service connections including 50-amp and 60-amp breakers at panel, and assessed installation area in basement utility space. Provided detailed replacement options for both standalone AC unit and complete HVAC system upgrade based on equipment age, current system failure, and home specifications.
Completed Platinum Level maintenance on a one-year-old Lennox furnace system with integrated humidifier. Performed comprehensive inspection of all internal components including electrical connections, control board, circuit breaker, and wiring harness. Inspected and serviced cylindrical drum-style humidifier unit, verified proper operation and water panel condition. Checked blower compartment assembly and gas line connections for proper installation and safety. Replaced 20x25x5 air filter and verified all access panels secured properly. All components found operating within normal parameters with no deficiencies noted during this first annual maintenance visit.
Completed Platinum Level maintenance on a 1-year-old Lennox HVAC system consisting of an outdoor condensing unit and indoor furnace. Performed comprehensive inspection of both indoor and outdoor equipment, replaced 20x25x5 air filter, checked all electrical connections and controls, verified proper refrigerant levels and pressures, inspected condensate drain system and PVC piping, tested system operation and safety controls, cleaned condenser coils, and confirmed proper airflow throughout the system. All components found operating within manufacturer specifications. System performing efficiently with no deficiencies noted.
Completed monthly platinum-level preventive maintenance on a 4-year-old residential HVAC system. Removed and cleaned the washable filter, which showed moderate dust accumulation, inspected all mechanical components including blower motor and electrical connections, and verified proper operation of the furnace unit installed in the utility closet. All PVC vent and condensate lines were checked for proper drainage and secure connections, and the system was found to be operating within normal parameters.
# HVAC Annual Maintenance Completed Performed second annual preventive maintenance visit on one-year-old residential HVAC system. Removed and replaced heavily soiled 20x25x5 air filter showing significant accumulation of dust and debris, which had substantially reduced airflow capacity. The filter exhibited uniform discoloration and dense particulate buildup consistent with a full year of operation in dusty conditions. Inspected outdoor condenser unit and confirmed proper operation. Completed standard maintenance procedures including system performance verification. Renewed annual maintenance agreement and collected payment as scheduled. System restored to optimal operating efficiency with new filtration in place.
Completed warranty follow-up service to address refrigerant leak on suction line. System was pumped down and leak repair performed on the copper suction line where significant corrosion and crystalline buildup were present. Visual inspection revealed thermal damage to interior cabinet panel and extensive white crystalline deposits on copper tubing and surrounding components, indicating previous refrigerant leak. Repaired compromised suction line connection point, cleaned affected area, and verified system integrity. All electrical connections inspected and confirmed secure. System restored to operational status with zero balance due from customer.
# Service Summary Completed first annual Platinum Level maintenance on a 2-year-old Lennox ML17XP1 system (Model: ML17XP1-024-230A01, Serial: 1923L63091). Performed comprehensive inspection and preventive maintenance procedures on the outdoor condensing unit, verified HFC-410A refrigerant charge of 6 lbs, confirmed electrical specifications at 208/230V 1-phase operation, and documented system condition with photos of manufacturer data plate and unit exterior. System operating within normal parameters with no deficiencies noted; 20x20x5 filter size confirmed for homeowner reference.
# Service Summary Responded to no heat call on 6-year-old system. Unit attempting ignition sequence but failing to light, resulting in cold air circulation. # Work Performed Upon arrival, verified thermostat was set to heat mode and calling for heating. Observed furnace cycling through ignition attempts without successful flame establishment. Confirmed electrical supply was intact with all breakers in proper position. Conducted diagnostic evaluation of ignition system components. Inspected gas valve, flame sensor, hot surface ignitor, and control board for proper operation. Tested gas supply pressure at manifold to verify adequate fuel delivery. Examined flame sensor for carbon buildup or deterioration that could prevent flame detection. Evaluated hot surface ignitor for proper resistance values and visual signs of cracking or degradation. Checked furnace control board for error codes and proper voltage output to ignition components. Verified proper grounding and electrical conne
Successfully installed a 20K BTU dual-zone mini-split system with both 110V/220V electrical circuits at the customer's residence. The outdoor condenser unit was properly mounted on a concrete pad with protected refrigerant and electrical lines running to the building, and all interior wiring was completed with appropriate terminal connections and color-coded wiring to ensure optimal system functionality.