> By: The Cooling Company
Require a C-wire or Lennox power module plus an outdoor sensor for correct control. Keep commissioning records, photos, and serial numbers for rebates and warranty. Call The Cooling Company at 17029308411 for installs in Las Vegas, Henderson, or North Las Vegas.
Key Takeaways
- Use a room-by-room Manual J load calculation (not a square-foot rule).
- Select equipment with Manual S and verify ducts with Manual D for comfort and efficiency.
- Avoid oversizing: short-cycling wastes fuel and can create uneven temperatures.
What is a Lennox iComfort dual fuel setup?
A Lennox iComfort dual fuel system pairs a heat pump with a gas furnace and uses the iComfort smart thermostat to manage changeover. The thermostat reads outdoor temperature, monitors runtime and equipment status, and follows programmed rules to pick heat sources. That logic helps the home use the most efficient source of heat while protecting the compressor and avoiding overlap between systems.
Beyond simple changeover, iComfort offers features such as minimum run times, compressor delay timers, outdoor sensor support, and lockouts for backup heat. These features cut energy use and reduce wear on components. For example, the thermostat can prevent the furnace from coming on until the heat pump has run long enough to determine it cannot keep up. This reduces start-stop cycling and keeps energy costs lower when the heat pump can still do the job.
How the iComfort coordinates heat pump and furnace calls
The iComfort uses a set of rules to determine which equipment to run. It reads the outdoor sensor and watches heat pump runtime, then applies the contractor-set thresholds to call the furnace only when the heat pump is inefficient or cannot maintain setpoint. The thermostat can also respect time-of-use electricity rates and other inputs if programmed. Good installers document these rules during commissioning so owners understand how changeover happens.
Core features homeowners will notice?
Homeowners often notice fewer furnace cycles and longer heat pump runs when the system is tuned right. The iComfort can show energy reports and runtime logs in its app. It also offers alerts for faults, which lets contractors respond faster. Many owners appreciate the remote insight into system behavior and the ability to adjust changeover settings after a brief observation period.
How does the thermostat protect the compressor and equipment?
Compressor protection and proper sequencing are key to a long-lived dual fuel setup. The iComfort enforces minimum run times and compressor delay timers to stop short cycling. Short cycles cause higher wear and can allow the compressor to overheat or fail prematurely. Minimum run times usually fall in the three-to-ten minute range, while compressor delays often add one to five minutes after a stop.
Installers use these timers to balance protection with responsiveness. Too long a delay can slow comfort recovery. Too short a delay risks frequent starts. The installer will tune these during commissioning and often change values based on the first two weeks of runtime data. Proper tuning extends equipment life and improves steady comfort.
Minimum run times and compressor delay explained?
Minimum run time is the shortest allowed continuous run for the compressor. It prevents rapid stop-start cycles. Compressor delay is the enforced wait time before a restart. The delay avoids immediate restarts that can occur from short thermostatic changes. Together, they reduce wear and stabilize performance.
Why installers document these settings
Documenting timers and lockouts is necessary for rebates and warranties in many programs. A clear commissioning report shows what was set and why. This report also helps future technicians troubleshoot without guessing prior settings. Owners should request a copy of the commissioning file and keep it with equipment records.
Changeover logic: How the iComfort decides when to use the furnace?
Changeover is based on several inputs and programmed rules. The outdoor sensor, heat pump runtime, equipment status, and configured lockouts all feed into the decision. The thermostat uses these inputs to avoid running both systems or calling the furnace when the heat pump could maintain comfort. This logic reduces energy and prevents unnecessary wear.
In practice, contractors pick a baseline outdoor temperature for automatic changeover, then tune it using logged run minutes and comfort feedback. For Summerlin, installers often start with a 32°F–40°F baseline and refine the setting based on the property's heat load and occupant comfort. The thermostat can also consider cost-based logic if electric and gas rates vary significantly.
What inputs affect changeover most
The most important inputs are outdoor temperature and recent heat pump runtime. The thermostat might also use compressor efficiency indicators or time-of-use rates. Combining multiple inputs gives a more accurate decision than relying on outdoor temperature alone. During commissioning, installers should note which inputs are active and why those choices were made.
Signs the changeover setting needs tuning?
Watch for frequent furnace starts when the outdoor temperature is still above the changeover threshold. Also check runtime logs. If the furnace runs often while the heat pump shows short runs, the heat pump may lack capacity or the setting may be too warm. Use the logs to guide small, incremental changes and retest.
Compatibility: Is my equipment ready for iComfort?
Compatibility depends on control terminals, control voltage, and the age of the equipment. Most modern Lennox furnaces and heat pumps work with iComfort thermostats. Older or proprietary controls might need a Lennox power module or an adapter to supply a clean C-wire and correct sequencing. Installers should inspect model tags and control boards during the first visit to avoid surprises.
As a rule, confirm that the furnace and outdoor unit have the standard control terminals: W, Y, O/B, G, R, and C. If any are missing or if the furnace cannot supply enough 24VAC current, the installer will recommend a power module. That module provides stable 24VAC and prevents thermostat reboots or incorrect equipment behavior.
Can I use the existing thermostat wiring?
Many homes can use their existing wiring if a C-wire is present. The iComfort needs R and C for power plus Y, O/B, W, and G for control signals in a dual-fuel setup. If a C-wire is missing, installers can run a new wire or add a Lennox power module. DIY homeowners can label wires and take photos for the installer. Always turn power off at the breaker before inspecting wires.
When a power module is necessary
Older furnaces sometimes cannot provide enough auxiliary power for a smart thermostat. In such cases, a Lennox power module or external transformer gives stable 24VAC. That avoids browning-out or intermittent thermostat reboots. Installers will recommend the module if they see weak control power or missing terminals during the initial inspection.
Wiring, sensors, and proper placement
Correct wiring and outdoor sensor placement are central to a reliable dual fuel control. The outdoor sensor should be shaded and away from exhaust vents or reflective surfaces. A sensor in direct sun or near an exhaust will show a biased temperature and can force premature changeover. For wiring, have stable 24VAC power and clearly labeled wires for each terminal.
Installers should test for continuity and proper voltage, then photograph the connections. These photos help with future troubleshooting and support rebate paperwork. Label both ends of the thermostat wires to prevent incorrect connections that could cause simultaneous heat calls or erratic behavior.
How to confirm correct wiring labels
Match each thermostat wire to the corresponding terminal on the furnace and outdoor unit. Use a multimeter to confirm 24VAC between R and C. Check control signals for continuity. Label both ends with durable tags and take clear photos. Proper labels save time on service calls and prevent costly wiring mistakes.
Best locations for the outdoor sensor
Mount the outdoor sensor on a north or shaded wall to avoid sun bias. Keep it away from exhausts, dryer vents, or reflective surfaces. Place it at an elevation representative of ambient conditions, not in confined courtyards that trap heat. Use a weatherproof housing and run a short conduit or cable to the thermostat for protection.
Professional installation and commissioning process
A full professional install includes wiring verification, thermostat mounting, outdoor sensor placement, and system commissioning. The technician checks furnace and heat pump control voltages, confirms terminal functions, and sets changeover logic. They also configure minimum run times, compressor delay timers, and any lockouts required to keep the systems from running together.
Good installers provide a commissioning report that includes photos, serial numbers, and runtime logs. This paperwork is essential for NV Energy rebates and many manufacturer warranty conditions. The installer should explain each setting and leave a copy of the report with the homeowner.
Tests run during commissioning
Technicians force a changeover and log start times, outdoor temperature, and run durations. They verify that only one heat source runs at a time. They also test compressor protection timers and backup heat lockouts. Safety checks such as pressure switch verification and basic airflow measurements are often included to ensure safe startup.
Typical installation time and expectations
A simple thermostat swap in a home with good wiring can finish in about an hour. A full dual-fuel setup, including sensor mounting and commissioning, typically takes 60 to 120 minutes. If a power module or new wiring is needed, the job can take longer. Your contractor should provide a written estimate with expected time on site and total costs.
Paperwork, rebates, and what you must keep
Rebate programs usually require model numbers, serial numbers, a signed commissioning checklist, and runtime logs. Contractors often need to include photos of wiring and sensor placement. Timely and accurate submission speeds approvals. Keep copies of invoices, the commissioning report, and any utility correspondence. Many programs also require the installer's license number and a clear scope of work.
Ask your contractor to assemble the rebate packet at signoff. That packet should include all the required documents in digital format where possible. Keep original copies in your personal files. If an auditor requests additional proof, having neat, labeled documentation avoids delays.
What the contractor should provide you
The installer should give you a signed commissioning checklist, model and serial numbers, invoice, and runtime logs. Include photos of wiring, sensor placement, and a thermostat screen shot that shows key settings. Also collect the installer’s license and contact details. These items make rebate submission and future service easier.
Local rebates and eligibility notes
NV Energy and regional programs sometimes offer incentives for smart thermostats or high-efficiency systems. Rules change, and many programs require professional installation and appropriate commissioning reports. Confirm current eligibility with your installer before purchase so your setup meets program requirements without rework.
Common post-install issues and how to spot them
Typical problems include wrong sensor placement, a missing or weak C-wire, and incorrect terminal mapping. These issues can cause improper changeover, unexpected furnace starts, frequent thermostat reboots, or poor comfort. Early follow-up in the first two weeks catches these before they cause major trouble.
Monitor the thermostat app for runtime reports and cycle counts. If you see many short runs under five minutes or repeated reboots, contact your installer. Fast follow-up preserves warranty rights and prevents further damage.
Reading initial runtime and cycle reports
Look at total minutes per day for both the heat pump and furnace. Note cycle counts and average run length. High furnace minutes above the chosen changeover temperature indicate the changeover may be set too warm or the heat pump lacks capacity. Share logs with your contractor for final tuning.
When to call for follow-up service
Call if you see runs under five minutes, frequent thermostat reboots, or communication errors in the app. Also call if comfort is poor despite long heat pump runtime. Many issues resolve remotely, but plan a field visit when wiring or sensor relocation is needed. Qualified technicians bring diagnostic tools and parts for fast fixes.
Final checklist before you hire a contractor
Confirm the technician will provide a signed commissioning checklist and runtime logs. Ask for photos of wiring and sensor placement and verify the installer will record serial numbers for the heat pump and furnace. Confirm whether the contractor will submit rebate paperwork on your behalf and whether firmware updates will run during commissioning. Clear expectations avoid delays with rebates and help ensure the system performs as intended.
Request a written scope of work and an itemized estimate. Ask the installer to describe the changeover baseline they plan to start with and how they will tune it. Finally, ensure the crew is NATE-certified or has equivalent credentials for residential HVAC work.
Ready to book your iComfort install?
Call The Cooling Company at 17029308411 to schedule an on-site compatibility check and free estimate. Our team serves Las Vegas, Henderson, and North Las Vegas. We send NATE-certified technicians who have Lennox experience and provide a written scope, rebate checklist, and transparent pricing. If you are outside our service area, ask your contractor for NATE certification and a full commissioning report to match these standards.
How to get a free estimate
Call 17029308411 or request a site check to confirm compatibility and wiring. The Cooling Company will test control voltages, inspect terminals, and check sensor mount locations. You receive a clear written scope and a rebate-ready checklist. Our techs will explain wiring options, such as adding a power module or running a C-wire when needed.
What to expect on the day of service
Expect a detailed work order listing tasks, expected time on site, and final costs. Technicians may ask for recent utility bills if you want cost-based tuning. On the day of service, allow two hours for typical installs. Complex wiring or equipment changes may need more time. The crew will leave a commissioning report and photos at completion.
Learn More
This aspect deserves careful consideration as you evaluate options for dual fuel systems and smart thermostats. Talk with qualified professionals and compare written scopes from multiple contractors when possible. Document details and keep them with your equipment records for future reference. Careful planning and good documentation produce better long-term results.
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About The Cooling Company
The Cooling Company has been serving the Las Vegas valley with professional HVAC services for over a decade. Our team of licensed, NATE-certified technicians specializes in air conditioning repair, heating system maintenance, and complete HVAC installations. We're committed to providing honest, reliable service with upfront pricing and a 100% satisfaction guarantee on all work performed.
- Phone: (702) 930-8411
- Reviews: 4.9/5 stars (500 reviews) - See reviews
Service Areas
We proudly serve homeowners and businesses throughout the Las Vegas metropolitan area, including Las Vegas, Henderson, and North Las Vegas. Our service technicians are available for same-day appointments in most areas, with emergency service available 24/7 for urgent HVAC issues.
Sources and further reading
- Energy.gov – HVAC Efficiency Basics
- EPA Indoor Air Quality (IAQ)
- ASHRAE Technical Resources
- DOE Better Buildings – HVAC
- U.S. Department of Energy (Energy.gov) (accessed 2026-01-02)
- U.S. Environmental Protection Agency (EPA) (accessed 2026-01-02)
- ASHRAE (Standards and guidance) (accessed 2026-01-02)
- ENERGY STAR (Heating & cooling) (accessed 2026-01-02)
Call to action
Ready to upgrade to a Lennox iComfort dual-fuel setup in the Las Vegas area? Put simply, call The Cooling Company now at 17029308411. We serve Las Vegas, Henderson, and North Las Vegas and provide full installs, commissioning, and rebate paperwork. If you are outside our area, ask for NATE-certified technicians and follow the commissioning checklist above when hiring locally.
How does this affect homeowners?
Following the proper process ensures optimal results and reduces common mistakes. Start by gathering wiring photos, recent utility bills, and model tags. Use the commissioning checklist when you hire a contractor. This planning helps you get a smooth install and places you in the best position for rebates and warranty coverage.
Taking these steps helps you avoid costly callbacks and gives you clearer, more efficient system performance over the life of the equipment.