Bosch / Climate 5000 Gen 4
Bosch Climate 5000 G4 18k Max R-454B 208/230V 3-Zone Mini-Split
The Bosch Climate 5000 3-Zone 18k Max Performance (BMS500-AAM018-1CSXHD) is the cold-climate three-zone on current low-GWP R-454B refrigerant, and one of the top-scoring multi-zones in our catalog. It pairs a certified nominal SEER2 of 25 with EER2 15 and HSPF2 10.4, is ENERGY STAR certified, and is AHRI cold-climate designated.
Heating holds essentially flat into deep cold - 20,000 BTU at 47F, 20,000 BTU at 17F, and 19,000 BTU at 5F - genuine deep-cold performance backed by Bosch's engineering and warranty reputation. Dealer-quoted; professional installation required.
3 zonesProfessional installCurrent
Refrigerant generation
R-454B - current-generation refrigerant
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Image: Hydrowest Products
Data completeness: 97%
- Last sourced
- Jul 28, 2026
SplitAtlas score
9.3 / 10
Cooling efficiencyTop 10%
(25.0 SEER2) among 18k systems
Heating efficiencyTop quartile
(10.4 HSPF2) among 18k systems
Cold-weather performanceAbove average
(5F certified capacity: 95% of the 47F rating; -22 F heating floor) among 18k systems
WarrantyTop quartile
(10 yr parts / 10 yr compressor) across the catalogue
Feature setTop quartile
(6 verified features) across the catalogue
Documentation & partsBelow average
(7 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
This is a professionally installed, quote-only system, so we can't score its price. Get an installed quote to compare real cost.
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Key ratings
Buyer review snapshot
Best for / skip if
Best for
- 3-zone projects in the 18k outdoor capacity class.
- Top efficiency shortlists; SEER2 is 25.
Install difficulty
Professional flared-line install
- Electrical: 230V; MCA 17.5 A; breaker/fuse 20 A.
- Line set: Flared line connections; precharged 24.6 ft; max 196.8 ft.
- 3-zone condenser; indoor-head matching and branch layout are part of the job.
Availability and price context
This system needs a professional install, so its real price is an installed quote that depends on your home. We don't link to a listing for this exact model; get installation quotes to price it.
Source date
- Model data sourced
- Jul 28, 2026
- Page reviewed
- Jul 28, 2026
- Source-backed records
- 4
- Newest source retrieved
- Jul 28, 2026
Warranty tiers
- Base
- 10 yr parts / 10 yr compressor - limited residential warranty terms
The score uses Base. Additional published terms are shown for reference and not counted in the score.
Model context
- Install path
- This is professional-install equipment; price it with an installed quote.
- Structured ratings
- Certification: ENERGY STAR certified and AHRI cold-climate designated. Refrigerant: current low-GWP R-454B. Minimum heating ambient: -22 F.
Strengths
- Cold-climate three-zone on current low-GWP R-454B refrigerant.
- Heating holds flat in deep cold - 20,000 BTU at both 47F and 17F, 19,000 BTU at 5F.
- Certified nominal SEER2 25 / EER2 15 / HSPF2 10.4, ENERGY STAR certified.
- AHRI cold-climate designated; Bosch global engineering and warranty reputation.
Weaknesses
- Costs a bit more than the standard three-zone for the cold-climate tuning.
- 19,000 BTU across three zones is modest per room - size each head.
Climate suitability
- Minimum heating ambient
- -22 F[1]
- Certified heating at 5F
- 19,000 BTU/hNon-Ducted Indoor Units[2]
- Rated heating at 17F
- 20,000 BTU/hNon-Ducted Indoor Units[2]
- Rated heating at 47F
- 20,000 BTU/hNon-Ducted Indoor Units[2]
Specifications
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- Manufacturer
- Bosch
- Brand
- Bosch
- Product line
- Climate 5000 Gen 4
- Model number
- BMS500-AAM018-1CSXHD
- Indoor unit model
- Depends on the indoor units you choose
- Outdoor unit model
- BMS500-AAM018-1CSXHD
- Number of zones
- 3
- Max indoor units
- 3 units[1]
- Rated cooling capacity
- 19,000 BTU/hNon-Ducted Indoor Units[2]
- Rated heating capacity
- 20,000 BTU/hNon-Ducted Indoor Units[2]
- Voltage
- 230 V[1]
- MCA
- 17.5 A[1]
- Maximum fuse or breaker size
- 20 A[1]
- Breaker needed
- not published
- SEER2
- 25 SEER2Non-Ducted Indoor Units[2]
- EER2
- 15 EER2Non-Ducted Indoor Units[2]
- HSPF2 (Region 4)
- 10.4 HSPF2Non-Ducted Indoor Units[2]
- HSPF2 (Region 5)
- Varies by indoor-unit combination
- COP
- not published
- COP at 47F
- 4 COP[1]
- COP at 5F
- 2 COPNon-Ducted Indoor Units[2]
- Minimum outdoor heating temperature
- -22 F[1]
- Minimum outdoor cooling temperature
- -22 F[1]
- Maximum outdoor temperature
- 122 F[1]
- Indoor noise range
- Depends on the indoor units you choose
- Outdoor noise rating
- 61.5 dBA[1]
- Indoor weight
- Depends on the indoor units you choose
- Outdoor weight
- 137.35 lb[1]
- Refrigerant
- R-454B[2]
- Refrigerant charge
- 78.31 oz[1]
- Manufacturer coverage
- not published
- Line-set size
- 1/4 in x 3 liquid / 3/8 in x 3 suction
- Included line-set length
- Depends on the indoor units you choose
- Maximum line-set length
- 196.8 ft[1]
- Max line set per indoor
- 98.4 ft[1]
- Maximum elevation difference
- 49.2 ft[1]
- Max height between indoor units
- 33 ft[1]
- Wi-Fi support
- Depends on the indoor units you choose
- Energy Star status
- ENERGY STAR certified[3]
- AHRI certification number
- 215223316Non-Ducted Indoor Units[2]
- Warranty
- Base: 10 yr parts / 10 yr compressor (limited residential warranty terms). Score uses Base.. 10-year compressor / 10-year parts limited warranty
- Install path
- Professional install
- Retail price
- Installed quote only
- Available retailers
- not published
- Manual links
- AHRI public detail 215223316, ENERGY STAR exact row 215223316, Bosch Climate 5000 R-454B current official product page, BMS500-AAM018-1CSXHD Bosch Climate 5000 Gen 4 Max Performance submittal, Bosch ductless engineering submittal sheet index, Bosch Climate 5000 R-454B warranty summary
- Specification sheet
- BMS500-AAM018-1CSXHD Bosch Climate 5000 Gen 4 Max Performance submittal
- Last sourced date
- Jul 28, 2026
Installation considerations
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- Liquid line
- 1/4 in x 3[1]
- Suction line
- 3/8 in x 3[1]
- Line connection type
- Flared line connections[1]
- Precharged length
- 24.6 ft[1]
- Included line-set length
- Depends on the indoor units you choose
- Maximum line-set length
- 196.8 ft[1]
- Max line set per indoor
- 98.4 ft[1]
- Max height between indoor units
- 33 ft[1]
- Indoor dimensions
- Depends on the indoor units you choose
- Outdoor dimensions
- 37.24 x 16.14 x 31.89 in[1]
- Indoor weight
- Depends on the indoor units you choose
- Outdoor weight
- 137.35 lb[1]
- Drain size
- not published
Related systems and guides
- More Bosch systems
- Blueridge XM3 All Climate Plus 18k R-454B 208/230V 3-Zone Mini-Split
- Carrier Infinity 25 18k R-454B 208/230V 3-Zone Mini-Split
- Bosch Climate 5000 G4 18k Regular R-454B Mini-Split
- Bosch Climate 5000 G4 24k Max R-454B Mini-Split
- Guide library
- Mini split buying guide
- Single-zone vs multi-zone mini splits
- Troubleshooting
- Do mini splits work in cold weather?
- Bosch mini split review: is Bosch any good?
- The best multi-zone mini splits of 2026
- The best 3-zone mini splits of 2026
- How to size a multi-zone mini split
- Not every multi-zone condenser lets you mix head types
- How much does a multi-zone mini split cost?
- The best cold-climate mini splits of 2026
- The best mini splits for heating of 2026
- Mini split heating capacity in the cold: what your unit actually delivers at 5F
- One room won't heat or cool on a multi-zone mini split
- Mini split not heating
- Mini split indoor unit freezing up
- Mini split Wi-Fi not connecting
- Your mini split is showing a refrigerant leak code
- Line sets
- Line-set covers
Frequently asked questions
- Can I install the Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Max Performance (BMS500-AAM018-1CSXHD) myself, or do I need a pro?
- Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Max Performance (BMS500-AAM018-1CSXHD) 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 Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Max Performance (BMS500-AAM018-1CSXHD) keep heating in a cold winter?
- The AHRI/ENERGY STAR certification lists 19,000 BTU/h of heating capacity at 5F. Rated heating operation extends down to -22 F. Certified heating efficiency is 10.4 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 Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Max Performance (BMS500-AAM018-1CSXHD) need?
- Published electrical requirements: 230 V voltage, 17.5 A minimum circuit ampacity, and 20 A 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 from the outdoor unit to one indoor head is 98.4 ft. The combined piping limit across all heads is 196.8 ft. The outdoor unit's factory charge covers up to 24.6 ft of line; longer runs need added refrigerant. Measure the planned routing before ordering.
- What warranty does the Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Max Performance (BMS500-AAM018-1CSXHD) carry?
- The manufacturer publishes these warranty tiers: Base: 10 yr parts / 10 yr compressor (limited residential warranty terms). Score uses Base.. Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.
Data sources
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- Bosch Thermotechnology Corp.: BMS500-AAM018-1CSXHD Bosch Climate 5000 Gen 4 multi-zone engineering submittalSourced - manufacturer technical document
Covers Frequency, Maximum breaker size, Maximum fuse size, Minimum circuit ampacity, Phase, Voltage and more
- Air-Conditioning, Heating, and Refrigeration Institute: AHRI public detail 215223316Sourced - AHRI directory
Covers AHRI certification number, performance_spec.cold_climate_designation, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity and more
- U.S. Environmental Protection Agency ENERGY STAR: ENERGY STAR exact row check for AHRI 215223316Sourced - Energy Star listing
Covers Energy Star status
- Bosch Thermotechnology Corp.: Bosch Climate 5000 Ductless System Mini-Split Heat Pump R-454B product pageSourced - manufacturer product page
Covers Legacy compressor warranty value, Legacy warranty value, Base compressor warranty, Base warranty conditions, Base parts warranty, Warranty notes
Last updated
Jul 28, 2026