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      1.5-ton central heat pump · Merit ML17XP1 Series

      Lennox ML17XP1-018-230A

      Average cooling efficiency and below average heating efficiency for a 1.5-ton central heat pump, but not rated for cold climates.

      Ranks #80 of 170 1.5 ton central heat pumps for cooling efficiency, and costs about $549 a year to run in a mixed climate like Atlanta.

      SEER2
      16.8 Cooling efficiency over a season
      Average · beats 45%
      HSPF2
      8.5 Heating efficiency over a season
      Below average · beats 38%
      EER2
      14.0 Cooling efficiency on a 95°F day
      Excellent · beats 98%
      Heat at 5°F
      9,700 BTU/h46% of its 47°F output
      Very good · beats 70%

      A good fit if…

      • You want a choice of indoor units - 481 certified pairings.

      Think twice if…

      • You often see nights below 0°F - it is not cold-climate certified.
      • You mainly need heat - its HSPF2 is below average for central heat pumps.
      • You want the newest refrigerant - it uses R-410A, which is being phased down.
      • Comfort and noise matter - a single-stage compressor runs only full-on or off.

      Calculate my running cost

      Details

      Specifications1.5 ton, R-410A
      General
      BrandLennox
      Outdoor unit modelML17XP1-018-230A
      SeriesMerit ML17XP1 Series
      TypeCentral heat pump
      Nominal size1.5 ton
      CompressorVariable-speed units run longer at low powerSingle stage
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceJanuary 5, 2022
      Last certifiedOctober 27, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better16.8 (range 15.2-16.8)
      EER2Efficiency at 95°F outdoors12.2-14.0
      Cooling capacity18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better7.8-8.5
      Capacity at 47°F16,000-18,000 BTU/h
      Capacity at 17°F10,200-12,100 BTU/h
      Capacity at 5°F7,500-9,700 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.90-2.16
      ENERGY STAR cold climateNo
      Heating output as it gets colder46% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with CHX35-24A-**-*+TDR at the standard test temperatures, in BTU/h:

      Certified matchups481 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. The 60 highest-rated of 481 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      CHX35-24A-**-*+TDRSL280UH060NV36A*16.814.08.18,200210039430
      CHX35-30B-**-*+TDRSL297UH060NV36B*16.814.08.17,800210039525
      CHX35-24B-**-*+TDRSL280UH090V36B*16.814.08.18,400210039470
      CHX35-30B-**-*+TDRML180UH070V48B*16.814.08.18,000210039504
      CHX35-30B-**-*+TDRSL280UH080NV48B*16.814.08.18,000210039521
      CX35-30B+TDRSL280UH090V36B*16.814.08.18,000210039730
      CX35-30B+TDRSL280UH080NV48B*16.814.08.17,800210039728
      C35-30B+TDR+TXVSL280UH090V36B*16.814.08.18,000210039284
      CHX35-24B-**-*+TDRSL280UH080NV48B*16.814.08.18,400210039468
      C35-30B+TDR+TXVSL280UH080NV48B*16.814.08.17,800210039282
      CX35-30B+TDRML180UH070V48B*16.813.58.18,000210039706
      C35-30B+TDR+TXVML180UH070V48B*16.813.58.18,000210039258
      CK40CT-30B-0*+TDRSL280UH090V36B*16.814.08.18,000214623409
      CK40HT-24A-0*+TDRSL280UH060NV36A*16.814.08.18,200214623215
      CK40HT-24B-0*+TDRSL280UH090V36B*16.814.08.18,400214623248
      CK40HT-24B-0*+TDRSL280UH080NV48B*16.814.08.18,400214623247
      CK40HT-30B-0*+TDRML180UH070V48B*16.814.08.18,000214623269
      CK40HT-30B-0*+TDRSL280UH080NV48B*16.814.08.18,000214623283
      CK40HT-30B-0*+TDRSL297UH060NV36B*16.814.08.17,800214623287
      CK40CT-30B-0*+TDRML180UH070V48B*16.813.58.18,000214623394
      CK40CT-30B-0*+TDRSL280UH080NV48B*16.814.08.17,800214623408
      C35-30A+TDR+TXVEL280UH070XE36A*16.813.58.07,600210039203
      CHX35-30B-**-*+TDRML193UH070XE36B*16.813.58.07,600210039511
      CHX35-30B-**-*+TDRML180UH070V36B*16.814.08.07,700210039501
      CHX35-30B-**-*+TDRSLP99UH070XV36B*16.814.08.07,800210039526
      CHX35-30B-**-*+TDRSL297UH040NV36B*16.814.08.07,800210039524
      CX35-30B+TDRSL297UH060NV36B*16.813.58.07,800210039736
      C35-30A+TDR+TXVSL280UH060NV36A*16.814.08.07,900210039218
      CX35-30A+TDREL280UH070XE36A*16.813.58.07,600210039649
      CX35-30A+TDREL280UH070E36A*16.813.58.07,600210039647
      CX35-30B+TDRSL297UH040NV36B*16.813.58.07,800210039734
      CX35-30B+TDREL280UH090E36B*16.814.08.07,600210039688
      C35-30B+TDR+TXVSL297UH060NV36B*16.813.58.07,800210039289
      C35-30B+TDR+TXVSLP99UH070XV36B*16.813.58.07,800210039291
      CHX35-30B-**-*+TDREL280UH090E36B*16.814.08.07,600210039489
      CX35-30A+TDRSL280UH060NV36A*16.814.08.07,900210039662
      CHX35-30B-**-*+TDRML180UH070E36B*16.813.58.07,700210039500
      C35-30B+TDR+TXVEL280UH090E36B*16.814.08.07,600210039240
      CX35-30B+TDRSLP99UH070XV36B*16.813.58.07,800210039738
      C35-30B+TDR+TXVSL297UH040NV36B*16.813.58.07,800210039287
      CHX35-30B-**-*+TDRML193UH045XE36B*16.813.58.07,900210039509
      C35-30A+TDR+TXVEL280UH070E36A*16.813.58.07,600210039202
      CHX35-30B-**-*+TDREL297UH070XV36B*16.814.08.07,800213194349
      C35-30B+TDR+TXVEL297UH070XV36B*16.813.58.07,800213194341
      CX35-30B+TDREL297UH070XV36B*16.813.58.07,800213194353
      CHX35-30B-**-*+TDRML180UH070XE36B*16.813.58.07,700212945037
      CK40CT-30B-0*+TDRSL297UH040NV36B*16.813.58.07,800214623411
      CK40CT-30B-0*+TDRSL297UH060NV36B*16.813.58.07,800214623412
      CK40CT-30B-0*+TDRSLP99UH070XV36B*16.813.58.07,800214623413
      CK40HT-30B-0*+TDREL280UH090E36B*16.814.08.07,600214623260
      CK40HT-30B-0*+TDRML180UH070E36B*16.813.58.07,700214623267
      CK40HT-30B-0*+TDREL297UH070XV36B*16.814.08.07,800214623266
      CK40HT-30B-0*+TDRML180UH070XE36B*16.813.58.07,700214623270
      CK40HT-30B-0*+TDRML180UH070V36B*16.814.08.07,700214623268
      CK40HT-30B-0*+TDRML193UH045XE36B*16.813.58.07,900214623275
      CK40HT-30B-0*+TDRML193UH070XE36B*16.813.58.07,600214623276
      CK40HT-30B-0*+TDRSL297UH040NV36B*16.814.08.07,800214623286
      CK40HT-30B-0*+TDRSLP99UH070XV36B*16.814.08.07,800214623288
      CK40CT-30A-0*+TDREL280UH070E36A*16.813.58.07,600214623366
      CK40CT-30A-0*+TDREL280UH070XE36A*16.813.58.07,600214623367
      Yearly running cost in 10 large cities$503-$1,303

      At each state's average electricity price and the city's typical heating and cooling hours.

      Questions5
      What is the SEER2 rating of the Lennox ML17XP1-018-230A?
      The Lennox ML17XP1-018-230A is rated at up to 16.8 SEER2 and 14.0 EER2 for cooling and up to 8.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 481 certified matchups SEER2 ranges from 15.2-16.8.
      Is the Lennox ML17XP1-018-230A good for cold climates?
      It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 1.5-ton model.
      How much does the Lennox ML17XP1-018-230A cost to run per year?
      At its rated efficiency it costs about $503-$1,303 a year in electricity in large U.S. cities, depending on climate and local rates - for example $614 in Phoenix and $1,084 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Which indoor units work with the Lennox ML17XP1-018-230A?
      ENERGY STAR lists 481 certified combinations for this outdoor unit. The highest-rated ones use CHX35-24A-**-*+TDR, CHX35-30B-**-*+TDR, CHX35-24B-**-*+TDR.
      What refrigerant does the Lennox ML17XP1-018-230A use?
      It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and R-32.

      Running cost and savings

      Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

      Heat pump $606/yrYou save $312/yrSee details ↓
      1. Where you live
      Adjust heating and cooling hours

      Filled in from your city's climate. Change them if you run the system much more or less than usual.

      2. The heat pump Lennox ML17XP1-018-230A
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $606
      Current system, per year
      $918
      You save per year
      $312
      Payback
      22.4 years
      Net after 10 years
      -$3,881

      Cooling $377Heating $229Electricity used: 3,790 kWhSaved vs. a minimum-efficiency heat pump: $97

      Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

      Similar 1.5 ton models

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      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of October 27, 2025. How we use the data.