Selbyville, DE
Selbyville, DE, has the kind of small-town character that makes people stay. What nobody signs up for is a heating system that quits in January or an air conditioner that surrenders in the middle of a Delaware heat wave. Custom Mechanical has been solving exactly those problems for Delmarva homeowners since 1981, building a reputation across Sussex County on three simple principles: show up fast, fix it right and treat every customer like a neighbor. In Selbyville, DE, that's not a marketing line. It's how we've done business for decades when delivering our honest heating and air conditioning services.
Slash Energy Bills With an Air Conditioning Service Plan in Selbyville, DE
Energy costs across the mid-Atlantic have climbed steadily over the past decade, and an inefficient HVAC system is one of the fastest ways to feel that pressure in your monthly budget. A neglected air conditioner can quietly consume up to 40% more electricity than a well-maintained AC system, turning every degree of comfort into an unnecessarily expensive proposition. Custom Mechanical's air conditioning service visits go well beyond a basic tuneup, encompassing full system diagnostics, coil cleaning, refrigerant verification, electrical testing, and airflow balancing that collectively restore efficiency and reduce operating costs. For Selbyville, DE, homeowners who want to take control of their energy bills, a scheduled AC service visit is the most cost-effective first step available.
24/7 Emergency Heating and Air Conditioning Response in Selbyville, DE
HVAC systems have a well-documented tendency to fail at the worst possible moments. Custom Mechanical offers 24/7 emergency heating and air conditioning service precisely because comfort emergencies don't follow a business schedule. Our service technicians arrive prepared, with fully stocked vehicles carrying the parts and tools needed to handle the most common system failures on the spot. First-visit resolution is a goal and standard we hold ourselves to because we understand what it means for a Selbyville family to be without heat or cooling while waiting on a return visit. Whether it's a furnace that won't ignite, a compressor that's seized or an air handler throwing error codes at midnight, Custom Mechanical answers the call every single time.
Build Long-Term Reliability With a Whole-Home Comfort Assessment
Many homeowners in established communities like Selbyville are living with HVAC systems and plumbing infrastructure that have quietly aged past their optimal performance window. Equipment that still technically runs isn't necessarily equipment that runs well, and the gap between "operational" and "efficient" can represent hundreds of dollars in wasted energy costs every year. Custom Mechanical's whole-home comfort assessments give Selbyville residents a clear, honest picture of where their systems stand today and what steps make the most sense for long-term performance and reliability.
Call Custom Mechanical to learn more about the heating and air conditioning services we offer in Selbyville, DE, including emergency HVAC repairs and installations.
Recent Jobs and Reviews in Selbyville, DE
Selbyville, DE at a glance
Custom Mechanical has completed 20 jobs in Selbyville, DE between September 2026 and October 2026.
The most recent job was on October 17, 2026.
Custom Mechanical has completed 213 jobs in Selbyville, DE in the last 12 months.
Job Locations and Reviews
Responded to an emergency call for a blank thermostat and water in the furnace pan on a ten-year-old unit. Inspection found a heavily clogged 20x25x5 media filter loaded with dust and debris that had restricted airflow and contributed to the water accumulation and loss of system operation. Replaced the dirty filter, cleared the water from the pan, and restored the system to normal operation.
Installed a Rinnai RX199iN tankless water heater with a brass service valve kit, thermal expansion tank, and 3/4" stainless steel flex gas line, with brass fittings and nipples for the water connections. Ran 2" Schedule 40 PVC venting with DWV elbows and replaced the existing oversized roof penetration with a 2" roof boot and new flashing, which restored a weathertight seal at the roof.
Performed scheduled heating maintenance on two systems, including inspection of the furnace cabinets, electrical components, and control boards. Verified blower motor amperage and control voltage with a true RMS clamp meter, and conducted combustion analysis with a flue gas analyzer, confirming 0 ppm CO, 95.4% efficiency, 6.8% CO₂, and 10.6% O₂ with a stack temperature of 98°F. Both units operated within normal parameters, with no visible damage, rust, or safety concerns noted.
Performed scheduled heating maintenance on two systems, verifying thermostat operation (system set to off, fan on auto, indoor temperature 73°F) and inspecting the control cabinet wiring, connections, and circuit board. Measured amperage draw with a true RMS clamp meter (3.75 A on the tested conductor) and observed no signs of frost, rust, or visible damage.
Performed scheduled heating maintenance on two systems, including a cooling operation check and inspection of the tankless water heater and plumbing. Verified combustion performance with a digital combustion analyzer, with readings showing O₂ at 8.5%, CO at 0 ppm, CO₂ at 8.2%, stack temperature of 96°F, and combustion efficiency of 96.9%, indicating safe and efficient operation.
Removed and disposed of the existing equipment and installed a new American Standard 2-ton 14 SEER heat pump with matching air handler, 10 kW electric heat package, filter rack, and Honeywell WiFi thermostat. Fabricated and installed metal duct transitions to adapt to the existing ductwork, replaced the outdoor disconnect and electrical whip, and reused the existing electrical, condensate, and power lines. Replaced the drain pan and float switch, and set the outdoor unit on a plastic pad with snow legs.
Performed comprehensive deep cleaning maintenance on two cooling systems. Conducted combustion analysis testing which revealed optimal performance readings with oxygen levels at 9.3%, carbon monoxide at 35 ppm, efficiency at 95.4%, carbon dioxide at 7.7%, and stack temperature at 100°F, confirming proper system operation and safety parameters.
Completed heating maintenance visit on two systems. Performed combustion analysis using Bacharach analyzer, which confirmed proper operation with oxygen reading at 14.3%, carbon monoxide at 56 ppm, efficiency at 92.6%, carbon dioxide at 4.4%, and stack temperature at 95°F, indicating systems are operating within acceptable parameters.
Responded to water leak at residential water heater cold inlet connection. Upon inspection, found significant corrosion and rust buildup on cold water supply line connection to Rheem water heater. The corroded fitting was causing active water seepage around the inlet connection point. Assessed the water heating system installation, which included an adjacent water softener unit and expansion tank in the utility space. Documented the condition of the compromised connection and surrounding plumbing infrastructure, including copper supply lines showing oxidation and the overall configuration of the mechanical systems. Provided assessment and documentation of the leak source for necessary repair work.
Performed comprehensive heating system maintenance check on residential HVAC unit. Conducted combustion analysis using digital analyzer, recording carbon monoxide levels at 12 ppm and verifying proper temperature differentials across system components. Replaced 20x25x5 air filter and confirmed all operational parameters within acceptable ranges for safe and efficient heating season operation.
Responded to non-emergent service call regarding condensate line installation concern following recent HVAC system installation. Upon arrival, found plastic condensate drain line protruding from bi-fold closet door opening where indoor air handler unit is located. Accessed Lennox air handler unit inside closet, assessed existing PVC condensate piping configuration and routing. Repositioned and secured condensate drain line to ensure proper clearance from bi-fold door operation, preventing interference and improving aesthetic appearance. Verified condensate drainage system functionality and confirmed proper pitch for gravity drainage. Documented completed work with photographs showing unit interior with PVC drain assembly and T-fitting configuration, as well as exterior view of closet door area. System operating properly with no further concerns noted.
Completed heating maintenance visit on two systems, including one dual fuel unit. Performed combustion analysis on both heating systems, confirming safe and efficient operation with CO levels at 38 ppm and 30 ppm respectively, efficiency readings at 95.8% and 93.9%, and proper stack temperatures. Replaced Aprilaire 760 water panel on humidifier as part of seasonal maintenance contract. All systems tested and operating within manufacturer specifications.
Performed comprehensive heating system maintenance and combustion analysis. System tested at 93.0% efficiency with oxygen levels at 9.5%, carbon monoxide at 50 ppm, carbon dioxide at 7.6%, and stack temperature at 107°F, all within acceptable operating parameters.
Replaced failed outdoor thermostatic expansion valve (TXV) and filter drier on 2015 Amana/Goodman air conditioning unit model ASZC160241AF. System was evacuated to proper vacuum levels and recharged with R-410A refrigerant, with vacuum gauge readings confirming system integrity at -23 microns before charging.
Completed scheduled heating maintenance visit at property with key access. Verified Honeywell ProSeries WiFi thermostat operation and confirmed proper temperature control functionality, with system maintaining programmed setpoints and displaying correct readings throughout inspection.
Performed routine heating maintenance and safety inspection on two residential heating systems. Conducted combustion analysis testing using calibrated analyzer, verifying oxygen levels at 10.5%, carbon monoxide at 24 ppm, combustion efficiency at 93.4%, carbon dioxide at 6.9%, and stack temperature at 103°F, with all readings within acceptable parameters for safe and efficient operation.
Completed full HVAC system replacement for downstairs residential area. Removed and properly disposed of existing equipment. Installed new Lennox EL19KPV-036 3-ton 19 SEER variable speed heat pump as outdoor unit, positioned on plastic pad with snow legs for proper drainage and elevation. Mounted unit included new Lennox CBK45UHVT-036 variable speed air handler in interior closet space with Lennox 10 kw electric heat pack for supplemental heating capacity. Fabricated and installed metal duct transitions to adapt new equipment to existing ductwork system, ensuring proper airflow and system efficiency. Reused existing condensate drain lines and verified proper drainage. Replaced outdoor disconnect and electrical whip to meet current code requirements and ensure safe electrical connection to new equipment. Reused existing power supply lines where applicable. Installed new Honeywell digital WiFi thermostat for enhanced climate control and remote access capabilities. Positioned filter at
Responded to service call for HVAC system seasonal changeover. Upon arrival, accessed ceiling-mounted duct damper system and manually switched damper positions from cooling mode to heating mode per homeowner's request. Verified Honeywell Home smart thermostat was functioning properly and displaying correct temperature readings. System ready for heating season operation.
Responded to no cooling complaint in group fitness room. Inspected thermostat wiring and found exposed conductors at wall junction box requiring attention. Customer's maintenance agreement has expired and renewal was discussed but not confirmed at time of service.
Responded to no cooling call on second floor unit. Upon arrival, found system inoperative and performed diagnostic evaluation. Inspected outdoor condensing unit and identified failed run capacitor with visible deterioration and compromised connections. Replaced defective capacitor, verified proper electrical connections, and tested system operation. Unit restored to normal cooling function with proper amperage draw and temperature differential confirmed.
