Carrier / Infinity 38MPRA/40MPHA legacy
Carrier Infinity Legacy 18k A/A R-410A 208/230V Mini-Split
A legacy 18,000 BTU Infinity pairing (38MPRA / 40MPHA) on 230V with older R-410A refrigerant, rated 26.2 SEER2, 14.5 EER2, and 12 HSPF2. Certified heating runs 18,000 BTU at 47F, dips to 12,300 BTU at 17F, then recovers to 16,400 BTU at 5F. It is not ENERGY STAR certified and not cold-climate designated.
1 zoneProfessional installLegacy
Image: Carrier
Data completeness: 100%
- Last sourced
- Jul 27, 2026
SplitAtlas score
8.9 / 10
Cooling efficiencyTop 10%
(26.2 SEER2) among 18k systems
Heating efficiencyTop 10%
(12.0 HSPF2) among 18k systems
Cold-weather performanceAbove average
(91.1% heat retained at 5F) among 18k systems
WarrantyAbove average
(10 yr parts / 10 yr compressor) across the catalogue
Feature setBottom quartile
(2 verified features) across the catalogue
Documentation & partsBelow average
(6 manuals; spec sheet) across the catalogue
Not evaluated
- Installation accessibility — not applicable (professional install)N/A
professional install - DIY-accessibility not applicable
- Price-to-value — not evaluatedN/A
quote-only - no retail price to evaluate
Key ratings
Buyer review snapshot
Best for / skip if
Best for
- Top efficiency shortlists; SEER2 is 26.2.
Skip if
- You are shopping for a current-generation recommendation; catalog lifecycle is LEGACY.
Install difficulty
Professional install
- Electrical: 230V.
Alternatives
- Blueridge XS6 Max Efficiency 18,000 BTU R-454B 208/230V (BXS6A18WM0 / BXS6A18UC0)
9.0 score / 18k / SEER2 25.6 / -22 F heating floor / 230V
Exact destination at Alpine Home Air: $2,359.00, checked Jul 24, 2026
Availability and price context
We could not verify a current retail price for this model. We could not find a published consumer price for this model when we last checked on 2026-07-27.
Purchase channel policy
Carrier's ductless warranty excludes products purchased over the Internet; buyers should treat public online carts as outside the warranty-covered purchase channel.
- Warranty consequence
- Warranty coverage does not apply to any product purchased over the Internet.
- Authorized channel
- Licensed HVAC technician installation with defective parts returned to the distributor through a registered servicing dealer; not an internet purchase.
Any online offer for this brand should be treated as a warranty-risk warning, not a recommendation.
Compare online-purchase warranty rules by brand
Source: Carrier Corporation: CAC/BDP Limited Warranty Certificate - Limited Warranty for Ductless Split Units; retrieved Aug 15, 2026.
Source date
- Model data sourced
- Jul 27, 2026
- Page reviewed
- Jul 27, 2026
- Source-backed records
- 3
- Newest source retrieved
- Jul 27, 2026
Warranty tiers
Warranty: 10 years parts and no separate compressor term published as standard.
Strengths
- Strong legacy efficiency at 26.2 SEER2 with a healthy 12 HSPF2.
- Certified 5F output recovers to 16,400 BTU, better than its 17F figure, per the older-generation data.
Weaknesses
- Runs on phased-down R-410A; the current R-454B Infinity 27 18k is the replacement to weigh.
- Not ENERGY STAR or cold-climate certified, and the dip-then-recover curve is an atypical legacy pattern.
Climate suitability
- Minimum heating ambient
- No model-specific value is published on the current Carrier consumer listing
- Rated heating at 5F
- 16,400 BTU/h[2]
- Rated heating at 17F
- 12,300 BTU/h[2]
- Rated heating at 47F
- 18,000 BTU/h[2]
Specifications
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- Manufacturer
- Carrier
- Brand
- Carrier
- Product line
- Infinity 38MPRA/40MPHA legacy
- Model number
- 40MPHAQ18XA3 indoor / 38MPRAQ18AA3 outdoor
- Indoor unit model
- 40MPHAQ18XA3
- Outdoor unit model
- 38MPRAQ18AA3
- Number of zones
- 1
- Max indoor units
- not published
- Rated cooling capacity
- 18,000 BTU/h[2]
- Rated heating capacity
- 18,000 BTU/h[2]
- Voltage
- 230 V[1]
- MCA
- No model-specific value is published on the current Carrier consumer listing
- Maximum fuse or breaker size
- No model-specific value is published on the current Carrier consumer listing
- Breaker needed
- not published
- SEER2
- 26.2 SEER2[2]
- EER2
- 14.5 EER2[2]
- HSPF2 (Region 4)
- 12 HSPF2[2]
- HSPF2 (Region 5)
- not published
- COP
- not published
- COP at 47F
- not published
- COP at 5F
- 1.95 COP[2]
- Minimum outdoor heating temperature
- No model-specific value is published on the current Carrier consumer listing
- Minimum outdoor cooling temperature
- No model-specific value is published on the current Carrier consumer listing
- Maximum outdoor temperature
- No model-specific value is published on the current Carrier consumer listing
- Indoor noise range
- No model-specific value is published on the current Carrier consumer listing
- Outdoor noise rating
- No model-specific value is published on the current Carrier consumer listing
- Indoor weight
- No model-specific value is published on the current Carrier consumer listing
- Outdoor weight
- No model-specific value is published on the current Carrier consumer listing
- Refrigerant
- R-410A[2]
- Refrigerant charge
- not published
- Manufacturer coverage
- not published
- Line-set size
- No model-specific value is published on the current Carrier consumer listing liquid / No model-specific value is published on the current Carrier consumer listing suction
- Included line-set length
- Professional installations use separately selected line sets
- Maximum line-set length
- No model-specific value is published on the current Carrier consumer listing
- Max line set per indoor
- not published
- Maximum elevation difference
- No model-specific value is published on the current Carrier consumer listing
- Max height between indoor units
- not published
- Wi-Fi support
- No model-specific value is published on the current Carrier consumer listing
- Energy Star status
- Not ENERGY STAR certified[3]
- AHRI certification number
- 202463634[2]
- Warranty
- Standard: 10 yr parts / no separate compressor term (eligible timely registered residential installation). Consumer Choice Warranty: 10-year parts-only or 5-year parts plus 3-year labor for eligible timely registered residential installations; terms and participating dealer requirements apply.
- Install path
- Professional install
- Retail price
- We could not find a published consumer price for this model when we last checked on 2026-07-27.
- Available retailers
- not published
- Manual links
- AHRI public directory record 202463634, ENERGY STAR exact check 202463634, Infinity 38MPRA/40MPHA legacy installation documentation locator, Carrier Infinity 38MPR legacy R-410A heat pump, HVACDirect exact Carrier offer check carrier-infinity-38mpra-40mpha-legacy-18k-r410a-230v, AHRI Appendix M1 public detail 202463634
- Specification sheet
- AHRI Appendix M1 public detail 202463634
- Last sourced date
- Jul 27, 2026
Electrical requirements
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- Voltage
- 230 V[1]
- Voltage range
- 208/230V[1]
- Phase
- 1[1]
- Frequency
- 60 Hz[1]
- MCA
- No model-specific value is published on the current Carrier consumer listing
- Breaker needed
- not published
- Maximum breaker size
- No model-specific value is published on the current Carrier consumer listing
- Maximum fuse size
- No model-specific value is published on the current Carrier consumer listing
- Maximum cooling current
- not published
- Maximum heating current
- not published
- Manufacturer wire notes
- not published
Installation considerations
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- Liquid line
- No model-specific value is published on the current Carrier consumer listing
- Suction line
- No model-specific value is published on the current Carrier consumer listing
- Line connection type
- not published
- Precharged length
- not published
- Included line-set length
- Professional installations use separately selected line sets
- Maximum line-set length
- No model-specific value is published on the current Carrier consumer listing
- Max line set per indoor
- not published
- Max height between indoor units
- not published
- Indoor dimensions
- No model-specific value is published on the current Carrier consumer listing
- Outdoor dimensions
- No model-specific value is published on the current Carrier consumer listing
- Indoor weight
- No model-specific value is published on the current Carrier consumer listing
- Outdoor weight
- No model-specific value is published on the current Carrier consumer listing
- Drain size
- not published
Related systems and guides
- More Carrier systems
- Infinity 35 18k
- Carrier Infinity 38MPRA/40MPHB legacy 18k 230V
Previous generation
- Carrier 230 V option
- Carrier sibling model
Previous generation
- Guide library
- Mini split buying guide
- Single-zone vs multi-zone mini splits
- Troubleshooting
- Carrier mini split review: is Carrier any good?
- The best 18,000 BTU mini splits of 2026
- The best DIY mini splits of 2026
- What "DIY mini split" actually means
- How to install a mini split (DIY overview)
- What size mini split do I need for a garage?
- Mini splits for a workshop or shop
- Why mini split installation quotes vary so much
- Do mini splits use gas or electric?
- Mini split remote not working
- Mini split Wi-Fi not connecting
- Mini split leaking water
- One room won't heat or cool on a multi-zone mini split
- Line sets
- Line-set covers
Frequently asked questions
- Can I install the Carrier Infinity 38MPRA/40MPHA legacy 18,000 BTU R-410A 208/230V (40MPHAQ18XA3 / 38MPRAQ18AA3) myself, or do I need a pro?
- Carrier Infinity 38MPRA/40MPHA legacy 18,000 BTU R-410A 208/230V (40MPHAQ18XA3 / 38MPRAQ18AA3) is built for professional installation: the line set must be flared, evacuated, and charged, which requires EPA-certified refrigerant handling. Installing it outside the manufacturer's requirements can void the warranty, so budget for a qualified HVAC installer.
- Will the Carrier Infinity 38MPRA/40MPHA legacy 18,000 BTU R-410A 208/230V (40MPHAQ18XA3 / 38MPRAQ18AA3) keep heating in a cold winter?
- The manufacturer publishes 16,400 BTU/h of heating output at 5F. Certified heating efficiency is 12 HSPF2. Match those numbers against your climate's design temperature - in cold regions, output at 5F matters far more than the nameplate capacity measured at 47F.
- What electrical circuit does the Carrier Infinity 38MPRA/40MPHA legacy 18,000 BTU R-410A 208/230V (40MPHAQ18XA3 / 38MPRAQ18AA3) need?
- Published electrical requirements: 230 V voltage, No model-specific value is published on the current Carrier consumer listing minimum circuit ampacity, and No model-specific value is published on the current Carrier consumer listing maximum breaker or fuse sizing. Confirm the final circuit against the unit nameplate and local code with a licensed electrician.
- How far can the outdoor unit be from the indoor head?
- The published maximum line-set length is No model-specific value is published on the current Carrier consumer listing. Longer runs than the included set allows typically mean added refrigerant and a pro visit, so measure the planned routing before ordering.
- What warranty does the Carrier Infinity 38MPRA/40MPHA legacy 18,000 BTU R-410A 208/230V (40MPHAQ18XA3 / 38MPRAQ18AA3) carry?
- The manufacturer publishes these warranty tiers: Standard: 10 yr parts / no separate compressor term (eligible timely registered residential installation). Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.
Data sources
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- Carrier Corporation: Carrier Infinity 38MPRB legacy R-410A heat pumpSourced - manufacturer product page
Covers Frequency, Phase, Voltage, Voltage range, Legacy warranty value, Standard compressor warranty status and more
- Air-Conditioning, Heating, and Refrigeration Institute: AHRI Appendix M1 public detail for 38MPRAQ18AA3 / 40MPHAQ18XA3Sourced - AHRI directory
Covers AHRI certification number, performance_spec.cold_climate_designation, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity and more
- ENERGY STAR: ENERGY STAR exact row check for AHRI 202463634Sourced - Energy Star listing
Covers Energy Star status
Last updated
Jul 27, 2026