Bosch / Climate 5000 Gen 4
Bosch Climate 5000 G4 18k Regular R-454B 208/230V 3-Zone Mini-Split
The Bosch Climate 5000 3-Zone 18k (BMS500-AAM018-1CSXRD) is the standard-tier three-zone on current low-GWP R-454B refrigerant, and one of the top-scoring multi-zones in our catalog. It reaches a certified nominal SEER2 of 25.1 - among the highest multi-zone efficiency we list - with EER2 14 and HSPF2 9.8, is ENERGY STAR certified, and is AHRI cold-climate designated.
It puts three heads on one 18,000 BTU outdoor unit backed by Bosch's global engineering and warranty reputation. Dealer-quoted (lead-gen); 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
8.7 / 10
Cooling efficiencyTop 10%
(25.1 SEER2) among 18k systems
Heating efficiencyAbove average
(9.8 HSPF2) among 18k systems
Cold-weather performanceBelow average
(71.1% heat retained at 5F; -13 F heating floor) among 18k systems
WarrantyAbove average
(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 25.1.
Install difficulty
Professional flared-line install
- Electrical: 230V; MCA 16 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
We could not verify a current retail price for this model. We could not find this exact model in stock at a retailer we work with when we last checked on 2026-07-28.
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
Warranty: 10 years parts and compressor as standard.
Model context
- Install path
- This is professional-install equipment; no verified current retail offer is attached.
- Structured ratings
- Certification: ENERGY STAR certified and AHRI cold-climate designated. Refrigerant: current low-GWP R-454B. Minimum heating ambient: -13 F.
Strengths
- Standard-tier three-zone on current low-GWP R-454B refrigerant.
- Certified nominal SEER2 25.1 / EER2 14 / HSPF2 9.8 - among the highest multi-zone efficiency we list.
- Bosch global engineering brand and warranty reputation.
Weaknesses
- 18,000 BTU across three zones is modest per room - size each head.
- For deep-cold heating, step up to the matching Max Performance three-zone.
Climate suitability
- Minimum heating ambient
- -13 F[1]
- Rated heating at 5F
- 13,500 BTU/hNon-Ducted Indoor Units[2]
- Rated heating at 17F
- 16,000 BTU/hNon-Ducted Indoor Units[2]
- Rated heating at 47F
- 19,000 BTU/hNon-Ducted Indoor Units[2]
Specifications
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- Manufacturer
- Bosch
- Brand
- Bosch
- Product line
- Climate 5000 Gen 4
- Model number
- BMS500-AAM018-1CSXRD
- Indoor unit model
- Indoor heads are selected separately on a multi-zone system
- Outdoor unit model
- BMS500-AAM018-1CSXRD
- Number of zones
- 3
- Max indoor units
- 3 units[1]
- Rated cooling capacity
- 18,000 BTU/hNon-Ducted Indoor Units[2]
- Rated heating capacity
- 19,000 BTU/hNon-Ducted Indoor Units[2]
- Voltage
- 230 V[1]
- MCA
- 16 A[1]
- Maximum fuse or breaker size
- 20 A[1]
- Breaker needed
- not published
- SEER2
- 25.1 SEER2Non-Ducted Indoor Units[2]
- EER2
- 14 EER2Non-Ducted Indoor Units[2]
- HSPF2 (Region 4)
- 9.8 HSPF2Non-Ducted Indoor Units[2]
- HSPF2 (Region 5)
- Certified per indoor-unit combination, not per outdoor unit
- COP
- not published
- COP at 47F
- 3.8 COP[1]
- COP at 5F
- 2.3 COPNon-Ducted Indoor Units[2]
- Minimum outdoor heating temperature
- -13 F[1]
- Minimum outdoor cooling temperature
- -13 F[1]
- Maximum outdoor temperature
- 122 F[1]
- Indoor noise range
- Indoor heads are selected separately on a multi-zone system
- Outdoor noise rating
- 59 dBA[1]
- Indoor weight
- Indoor heads are selected separately on a multi-zone system
- Outdoor weight
- 100.53 lb[1]
- Refrigerant
- R-454B[2]
- Refrigerant charge
- 61.73 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
- Indoor heads are selected separately on a multi-zone system
- 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
- Indoor heads are selected separately on a multi-zone system
- Energy Star status
- ENERGY STAR certified[3]
- AHRI certification number
- 215223328Non-Ducted Indoor Units[2]
- Warranty
- Standard: 10 yr parts / 10 yr compressor (limited residential warranty terms). 10-year compressor / 10-year parts limited warranty
- Install path
- Professional install
- Retail price
- We could not find this exact model in stock at a retailer we work with when we last checked on 2026-07-28.
- Available retailers
- not published
- Manual links
- AHRI public detail 215223328, ENERGY STAR exact row 215223328, Bosch Climate 5000 R-454B current official product page, HVACDirect exact-offer audit for BMS500-AAM018-1CSXRD, BMS500-AAM018-1CSXRD Bosch Climate 5000 Gen 4 Regular submittal, Bosch ductless engineering submittal sheet index, Bosch Climate 5000 R-454B warranty summary
- Specification sheet
- BMS500-AAM018-1CSXRD Bosch Climate 5000 Gen 4 Regular 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
- Indoor heads are selected separately on a multi-zone system
- 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
- Indoor heads are selected separately on a multi-zone system
- Outdoor dimensions
- 35.04 x 13.46 x 26.50 in[1]
- Indoor weight
- Indoor heads are selected separately on a multi-zone system
- Outdoor weight
- 100.53 lb[1]
- Drain size
- not published
Related systems and guides
- More Bosch systems
- Blueridge 18k model
- Bosch sibling model
- Bosch Climate 5000 Model C legacy R-410A 12k 115V
Previous generation
- Blueridge 230 V option
- 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 18,000 BTU mini splits of 2026
- 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
- 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 smells bad
- Mini split remote not working
- 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 Regular (BMS500-AAM018-1CSXRD) myself, or do I need a pro?
- Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Regular (BMS500-AAM018-1CSXRD) 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 Regular (BMS500-AAM018-1CSXRD) keep heating in a cold winter?
- The manufacturer publishes 13,500 BTU/h of heating output at 5F. Rated heating operation extends down to -13 F. Certified heating efficiency is 9.8 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 Regular (BMS500-AAM018-1CSXRD) need?
- Published electrical requirements: 230 V voltage, 16 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 is 196.8 ft, and the included line set comes pre-charged for 24.6 ft. 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 Bosch Climate 5000 Gen 4 3-Zone 18,000 BTU R-454B 208/230V Regular (BMS500-AAM018-1CSXRD) carry?
- The manufacturer publishes these warranty tiers: Standard: 10 yr parts / 10 yr compressor (limited residential warranty terms). 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-AAM018-1CSXRD 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 215223328Sourced - 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 215223328Sourced - 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, Standard compressor warranty, Standard warranty conditions, Standard parts warranty, Warranty notes
Last updated
Jul 28, 2026