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Bosch / Climate 5000 A/B legacy R-410A

Bosch Climate 5000 A B Legacy 9k Regular R-410A Mini-Split

Certified capacity
9,000 BTU/h[2]
SEER2
21.8 SEER2[2]
Heating floor
-13 F[1]
Voltage
230 V[1]
Install path
Professional install

A legacy 9k head from the older R-410A generation on a 230V circuit, this unit posts a SEER2 of 21.8, a healthy EER2 of 14.9, and an HSPF2 of 9.3. Heating is rated at 9,800 BTU at 47F and 7,300 BTU at 5F. It is a valid AHRI-certified unit, but it is not ENERGY STAR certified or cold-climate designated and runs the phased-down R-410A refrigerant.

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Error Codes
Bosch Climate 5000 A/B legacy R-410A wall-mounted indoor unit (BMS500-AAU012-1AHWXB) for Bosch Climate 5000 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA)

Image: Sid Harvey

Data completeness: 92%
Last sourced
Jul 26, 2026

SplitAtlas score

7.7 / 10

Methodology
Cooling efficiencyBelow average

(21.8 SEER2) among <=9k systems

Heating efficiencyBottom quartile

(9.3 HSPF2) among <=9k systems

Cold-weather performanceBelow average

(5F certified capacity: 74.5% of the 47F rating; -13 F heating floor) among <=9k systems

NoiseBelow average

(24.5 dBA indoor min / 55 dBA outdoor) among <=9k systems

WarrantyTop quartile

(10 yr parts / 10 yr compressor) across the catalogue

Feature setBottom quartile

(2 verified features) across the catalogue

Documentation & partsBottom quartile

(6 manuals; 18 error-code rows) 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

Rated cooling

9,000BTU/h[2]

Rated heating

9,800BTU/h[2]

Buyer review snapshot

Best for / skip if

Skip if

  • You are shopping for a current-generation recommendation; catalog lifecycle is LEGACY.

Install difficulty

Professional install
  • Electrical: 230V; MCA 10 A; breaker/fuse 15 A.
  • Line set: connection type not sourced; precharged 25 ft; max 82 ft.

Alternatives

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 26, 2026
Page reviewed
Jul 26, 2026
Source-backed records
4
Newest source retrieved
Jul 26, 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.

Review methodology

Strengths

  • EER2 of 14.9 gives it respectable peak cooling efficiency for a legacy head.
  • Still carries Bosch's dealer and warranty support.

Weaknesses

  • Uses R-410A, which faces tightening production and import limits going forward.
  • Neither ENERGY STAR certified nor cold-climate rated, with heat down to 7,300 BTU at 5F.

Climate suitability

Minimum heating ambient
-13 F[1]
Certified heating at 5F
7,300 BTU/h[2]
Rated heating at 17F
not published
Rated heating at 47F
9,800 BTU/h[2]

Specifications

Show
Manufacturer
Bosch
Brand
Bosch
Product line
Climate 5000 A/B legacy R-410A
Model number
BMS500-AAU009-1AHWXB indoor / BMS500-AAS009-1CSXRA outdoor
Indoor unit model
BMS500-AAU009-1AHWXB
Outdoor unit model
BMS500-AAS009-1CSXRA
Number of zones
1
Max indoor units
not published
Rated cooling capacity
9,000 BTU/h[2]
Rated heating capacity
9,800 BTU/h[2]
Voltage
230 V[1]
MCA
10 A[1]
Maximum fuse or breaker size
15 A[1]
Breaker needed
not published
SEER2
21.8 SEER2[2]
EER2
14.9 EER2[2]
HSPF2 (Region 4)
9.3 HSPF2[2]
HSPF2 (Region 5)
not published
COP
not published
COP at 47F
not published
COP at 5F
1.83 COP[2]
Minimum outdoor heating temperature
-13 F[1]
Minimum outdoor cooling temperature
-13 F[1]
Maximum outdoor temperature
122 F[1]
Indoor noise range
24.5-42 dB(A)[1]
Outdoor noise rating
55 dBA[1]
Indoor weight
19.8 lb[1]
Outdoor weight
61.7 lb[1]
Refrigerant
R-410A[2]
Refrigerant charge
38.8 oz[1]
Manufacturer coverage
not published
Line-set size
1/4 in liquid / 3/8 in suction
Included line-set length
Bosch submittals publish field piping sizes and precharged refrigerant length, but do not specify an included line set for these professional-install systems.
Maximum line-set length
82 ft[1]
Max line set per indoor
not published
Maximum elevation difference
33 ft[1]
Max height between indoor units
not published
Wi-Fi support
not published
Energy Star status
Not ENERGY STAR certified[3]
AHRI certification number
203991148[2]
Warranty
Base: 10 yr parts / 10 yr compressor (limited residential warranty terms). Score uses Base.. 10-year compressor / 10-year parts limited residential warranty; terms and field-installed component limits apply.
Install path
Professional install
Retail price
Installed quote only
Available retailers
not published
Manual links
AHRI public directory record 203991148, ENERGY STAR exact check 203991148, Climate 5000 Ductless Mini-Split Heat Pump (R-410A Version) discontinued page, Bosch Climate 5000 ductless mini-split submittal sheet directory, BMS500-AAU009-1AHWXB & BMS500-AAS009-1CSXRA Bosch Climate 5000 A/B legacy R-410A submittal
Specification sheet
not published
Last sourced date
Jul 26, 2026

Electrical requirements

Show
Voltage
230 V[1]
Voltage range
208/230V[1]
Phase
1[1]
Frequency
60 Hz[1]
MCA
10 A[1]
Breaker needed
not published
Maximum breaker size
15 A[1]
Maximum fuse size
15 A[1]
Maximum cooling current
not published
Maximum heating current
not published
Manufacturer wire notes
not published

Installation considerations

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Liquid line
1/4 in[1]
Suction line
3/8 in[1]
Line connection type
not published
Precharged length
25 ft[1]
Included line-set length
Bosch submittals publish field piping sizes and precharged refrigerant length, but do not specify an included line set for these professional-install systems.
Maximum line-set length
82 ft[1]
Max line set per indoor
not published
Max height between indoor units
not published
Indoor dimensions
32.9 x 7.8 x 11.0 in[1]
Outdoor dimensions
30.3 x 11.8 x 21.9 in[1]
Indoor weight
19.8 lb[1]
Outdoor weight
61.7 lb[1]
Drain size
not published

Related systems and guides

Frequently asked questions

Can I install the Bosch Climate 5000 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA) myself, or do I need a pro?
Bosch Climate 5000 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA) 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 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA) keep heating in a cold winter?
The AHRI/ENERGY STAR certification lists 7,300 BTU/h of heating capacity at 5F. Rated heating operation extends down to -13 F. Certified heating efficiency is 9.3 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 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA) need?
Published electrical requirements: 230 V voltage, 10 A minimum circuit ampacity, and 15 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 82 ft. The outdoor unit's factory charge covers up to 25 ft of line; longer runs need added refrigerant. Measure the planned routing before ordering.
What warranty does the Bosch Climate 5000 A/B legacy R-410A 9,000 BTU Regular (BMS500-AAU009-1AHWXB / BMS500-AAS009-1CSXRA) 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

Show
  1. Bosch Thermotechnology Corp.: BMS500-AAU009-1AHWXB & BMS500-AAS009-1CSXRA Bosch Climate 5000 A/B legacy submittalSourced - manufacturer technical document

    Covers Frequency, Maximum breaker size, Maximum fuse size, Minimum circuit ampacity, Phase, Voltage and more

  2. Air-Conditioning, Heating, and Refrigeration Institute: AHRI Appendix M1 public detail for BMS500-AAS009-1CSXRA / BMS500-AAU009-1AHWXBSourced - AHRI directory

    Covers AHRI certification number, performance_spec.cold_climate_designation, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity and more

  3. ENERGY STAR: ENERGY STAR exact row check for AHRI 203991148Sourced - Energy Star listing

    Covers Energy Star status

  4. Bosch Thermotechnology Corp.: Climate 5000 R-454B limited residential warranty statementSourced - 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 26, 2026