$8,971.00Original price was: $8,971.00.$8,727.00Current price is: $8,727.00.
3.5 Ton – Single Stage Heat Pump System
The Merit® Series 3.5 Ton – Single Stage Heat Pump System is a complete home comfort solution, including the ML14KP1-042 heat pump, CBK45UHPT-042-71 air handler, and ECB45-15CB-P electric heat kit. Enjoy reliable, energy-efficient heating and cooling with advanced safety features and fully 2025-compliant R-454B refrigerant.
Key Benefits: ✅ 3.5 Ton single-stage system for year-round comfort ✅ SEER2 14.3 and HSPF2 7.5 for efficient performance ✅ Quiet operation with sound levels as low as 74 dBA ✅ Complete bundle with heat pump, air handler, and heat kit
Upgrade your home’s heating and cooling with the 3.5 Ton – Single Stage Heat Pump System. This complete bundle pairs the ML14KP1-042 single-stage heat pump, CBK45UHPT-042-71 air handler, and ECB45-15CB-P electric heat kit, delivering reliable, energy-efficient, and quiet year-round comfort for your home.
AHRI#:215739991
SEER2: 14.3
SEER2: 14.3 & HSPF2: 7.5 Ratings
With a SEER2 of 14.3 and HSPF2 of 7.5, this 3.5 Ton – Single Stage Heat Pump System provides consistent cooling and heating while meeting 2025 refrigerant standards. It uses R-454B refrigerant, ensuring environmentally responsible operation and reduced greenhouse impact.
The ML14KP1-042 heat pump delivers standard-efficiency, single-stage heating and cooling for dependable indoor comfort. ENERGY STAR® certified and eligible for federal tax credits, it operates quietly at sound levels as low as 74 dBA. The high-efficiency outdoor coil optimizes heat transfer, and the direct-drive fan ensures long-lasting, quiet operation.
Supplemental Heating – Heat Kit: ECB45-15CB-P
The ECB45-15CB-P Electric Heat Kit provides rapid backup heat with helix-wound nichrome elements, precisely controlled limit switches, and factory-installed circuit breakers for safety. Controls are pre-wired and plug directly into the air handler for simplified installation.
Reliable Airflow – Air Handler: CBK45UHPT-042-71
The CBK45UHPT air handler ensures consistent airflow and energy-efficient operation. Its all-aluminum Quantum™ Coil resists corrosion, and the three-speed blower motor provides balanced circulation. The fully insulated cabinet reduces noise, while the Refrigerant Detection System (RDS) adds an extra layer of safety.
Why Choose the 3.5 Ton – Single Stage Heat Pump System?
Ideal for homeowners seeking a complete, dependable heating and cooling solution, this system offers consistent temperature control, efficient energy use, and quiet operation. Fully 2025-compliant with R-454B refrigerant, it provides peace of mind, reliable performance, and easy installation.
Key Benefits at a Glance
✅ Year-round comfort ✅ SEER2 14.3 and HSPF2 7.5 for efficient heating and cooling ✅ Quiet operation with sound levels as low as 74 dBA ✅ Complete bundle with heat pump, air handler, and electric heat kit ✅ Braze-free installation for modern HVAC setups ✅ Built-in Refrigerant Detection System (RDS) for added safety ✅ Fully 2025-compliant system with eco-friendly R-454B refrigerant
Heat Pump Overview
Model #ML14KP1-042
Merit® Series | ML14KP1 Heat Pump
Standard-efficiency, single-stage heat pump compatible with 2025-compliant refrigerants.
Energy Efficiency & Performance
Reliable Efficiency: Meets or exceeds 14.30 SEER2 and 7.50 HSPF2 for consistent, energy-conscious heating and cooling.
ENERGY STAR® Certified: Exceeds federal guidelines for energy-efficient performance.
Federal Tax Credit Eligible: Qualifies for the Energy Efficient Home Improvement Credit (IRC Section 25C).
High-Efficiency Outdoor Coil: Engineered for superior heat transfer and low air resistance to maximize efficiency.
Single-Stage Compressor: Operates at full capacity when on, delivering dependable performance.
Quiet Operation
Low Sound Levels: Operates as quietly as 74 dB for a peaceful indoor environment.
Direct-Drive Fan: Precision-balanced outdoor fan reduces noise and extends product life.
Durable Cabinet Construction: Heavy-gauge, galvanized steel with louvered coil guard, baked-on powder finish, and zinc-coated steel base protects against rust and corrosion.
Braze-Free Installation Flexibility: Compatible with braze-free fittings for easier and more adaptable installation.
Integrated Drainage: Built-in drainage holes prevent moisture buildup in the base pan.
Safety & Sustainability
Eco-Friendly Refrigerant: Uses R-454B, compliant with 2025 EPA regulations for low global warming potential (GWP).
Refrigerant Detection System (RDS): Required for systems with over four pounds of refrigerant. Detects leaks and automatically halts operation while activating the indoor blower to safely disperse refrigerant, ensuring safe, code-compliant performance.
Product Specifications:
Brand
Lennox
Catalog Number
25F51
Model/Part Number
ML14KP1-042-230
Base Unit of Measure
Unit(S)
Family
ML14KP1
Series
Merit
Product Voltage
208-230 VAC 1 Ph 60 Hz
Cooling Capacity
3.5 Ton
Product Depth
32.25 Inch
Product Width
32.25 Inch
Product Height
36.5 Inch
Type
Single-Stage Heat Pump
SEER2
14.3 SEER2
HSPF2
Meets or exceeds 7.5 HSPF2
Gross Weight
262 lbs.
Suction Line OD
7/8 Inch
Liquid Line OD
3/8 Inch
Energy Star Certified
Yes
Refrigerant Type
R-454B
Compressor Type
1 Stage
Heat Kit Overview
Model #ECB45-15CB
Product Overview
Lennox ECB45 Electric Heat Kits
ETL certified for safety and compliance.
Designed for field installation inside the unit cabinet.
Offered in multiple voltage and kilowatt options—refer to the specific Air Handler Tables for details.
Utilizes helix-wound nichrome heating elements positioned directly in the airstream, allowing for immediate heat transfer, reduced element temperatures, and extended lifespan.
Each element includes a precisely placed limit control with a fixed shut-off temperature and automatic reset functionality.
A secondary thermal cutoff limit control provides added protection in the event of high temperature conditions.
Control box and access panel are constructed from heavy-duty galvanized steel for enhanced durability.
Delivered factory-assembled with all controls pre-installed and pre-wired.
Low voltage electric heat controls connect to the air handler via a simple plug-in connection.
Circuit Breaker Models (CB)
All “CB” models include built-in circuit breakers for protection against overloads and short circuits.
Circuit breakers are factory-installed and pre-wired within the electric heat unit.
They are both current-sensitive and temperature-activated.
Include manual reset capability.
In many jurisdictions, these circuit breakers are recognized as a valid disconnecting means, removing the need for a separate field-installed disconnect switch.
Always refer to your local electrical code for installation requirements and compliance.
Brand
Lennox
Catalog Number
27A17
Model/Part Number
ECB45-15CB-P
Base Unit of Measure
Unit(S)
EAN / UPC
66255160140
Product Voltage
208/240v 1ph 60 hz
Gross Weight
5.25 LB
Family
ECB45
Heating Capacity
15 kW
Type
Electric Heat Kit with Circuit Breaker
Series
ECB45
Additional Information
(1) 60 Amp & (1) 25 Amp Circuit Breaker
For Use With
CBK45 & CBA25 Series Air Handlers
Product Width
11.5 Inch
Product Height
7.0 Inch
Product Depth
21.5 Inch
Air Handler Overview
Model #CBK45UHPT-042-71
Merit® Series | CBK45UHPT Air Handler
Standard-performance, standard-efficiency, three-speed air handler designed for 2025-compliant refrigerants.
Overview
The CBK45UHPT Air Handler delivers dependable performance and energy efficiency in an affordable package. Its all-aluminum Quantum™ Coil resists indoor corrosion, while the three-speed blower motor provides consistent air circulation throughout your home.
Factory-prepared for R-454B refrigerant, these -71 models also include a Refrigerant Detection System (RDS) for enhanced safety and compliance with 2025 standards.
Energy Efficiency
High-Efficiency Indoor Coil: Optimized for excellent heat transfer and low air resistance to maximize system efficiency.
Multi-Speed PSC Motor: Permanent Split Capacitor motor delivers reliable and efficient air circulation at an affordable cost.
Quiet Operation
Insulated Cabinet: Minimizes sound for quiet operation and helps prevent cabinet sweating in hot and humid conditions.
Reliable Performance
Quantum™ Coil Technology: Proprietary aluminum alloy exclusive to Lennox, designed to withstand harsh indoor conditions.
Antimicrobial Drain Pan: Reduces mold and mildew growth, improving indoor air quality and preventing drain line blockages.
SEER stands for Seasonal Energy Efficiency Ratio. It measures the cooling efficiency of an air conditioner or heat pump over an entire cooling season. Essentially, it tells you how much cooling output (BTUs) you get for every unit of energy (watt-hour) used.
Higher SEER = more efficient
SEER ratings have traditionally been used in the U.S. to compare energy efficiency across systems.
Example: A 14 SEER unit uses less electricity than a 10 SEER unit to produce the same cooling.
What is SEER2?
SEER2 is the updated efficiency rating standard that reflects new federal testing procedures implemented by the Department of Energy (DOE) in 2023. It measures efficiency more accurately by accounting for real-world conditions, including:
Energy usage in modern airflow and installation configurations
More realistic climate and seasonal variations
Changes in the refrigerants and equipment designs
Key difference: SEER2 ratings tend to be slightly lower than SEER ratings for the same unit, but they provide a truer representation of actual efficiency in your home.
Why SEER2 is the new standard
The DOE updated testing to better match how systems perform in real homes, rather than ideal lab conditions.
It encourages manufacturers to improve real-world efficiency, not just test-case efficiency.
For consumers, SEER2 ensures:
Better long-term energy savings
Improved comfort through more accurate performance expectations
Compliance with modern federal efficiency regulations
In short:
SEER = old efficiency measurement (ideal lab conditions)
SEER2 = modern, realistic efficiency standard (real-world performance)
Better quality = SEER2 units are designed and tested to give actual efficiency and savings, not just theoretical numbers.
Understanding EER vs EER2
What is EER?
EER stands for Energy Efficiency Ratio. It measures an air conditioner or heat pump’s efficiency at a single, specific outdoor temperature, usually 95°F.
Higher EER = more efficient at peak conditions.
Unlike SEER, which averages efficiency over a season, EER tells you how the unit performs under hot, steady-state conditions.
Example: A unit with an EER of 12 produces 12 BTUs of cooling for every watt of electricity consumed.
What is EER2?
EER2 is the updated testing standard introduced by the Department of Energy (DOE) to match the same real-world adjustments as SEER2.
Accounts for modern system designs, refrigerants, and installation configurations.
Measures efficiency more realistically under peak operating conditions, rather than just ideal lab setups.
Like SEER2, EER2 numbers are usually slightly lower than traditional EER, but they are a more accurate reflection of actual performance.
Why EER2 is the new standard
Ensures consistency with SEER2 testing methodology.
Reflects true cooling efficiency under extreme heat, where peak performance matters most.
Helps consumers understand real-world energy use and savings potential during the hottest days.
Meets modern federal efficiency regulations and encourages manufacturers to improve performance under actual conditions.
In short:
EER = old standard, measured under lab conditions at 95°F
EER2 = modern standard, measured under realistic, real-world peak conditions
Better quality = EER2 gives you true peak efficiency, not just theoretical performance.
