SplitAtlas

Bosch / Climate 5000 Gen 4

Bosch Climate 5000 G4 12k Regular R-454B Mini-Split

Certified capacity
12,000 BTU/h[3]
SEER2
25.5 SEER2[3]
Heating floor
-13 F[1]
Voltage
230 V[1]
Install path
Professional install

This is the 12k Climate 5000 for cold winters - the 230V sibling of the 115V model, and the one to choose if you actually heat with it. It puts out meaningfully more heat in the cold (a real step up at 17F over the 115V version) and carries the cold-climate rating the 115V head lacks, so a standard room stays warm through the season instead of fading.

It runs on current R-454B refrigerant and is ENERGY STAR certified. The price of that winter performance is a dedicated 230V circuit and a dealer install.

1 zoneProfessional installCurrent

Refrigerant generation

R-454B - current-generation refrigerant

Need this installed?

Get installation quotes
Error Codes
Bosch Climate 5000 Gen 4 R-454B wall-mounted indoor unit (BMS500-AAU012-1AHWXD) for Bosch Climate 5000 Gen 4 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD)

Image: Hydrowest Products

Data completeness: 95%
Last sourced
Jul 26, 2026

SplitAtlas score

8.9 / 10

Methodology
Cooling efficiencyTop quartile

(25.5 SEER2) among 12k systems

Heating efficiencyTop quartile

(10.6 HSPF2) among 12k systems

Cold-weather performanceBelow average

(5F certified capacity: 70% of the 47F rating; -13 F heating floor) among 12k systems

NoiseAbove average

(18 dBA indoor min / 56 dBA outdoor) among 12k systems

WarrantyTop quartile

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

Feature setTop quartile

(6 verified features) across the catalogue

Documentation & partsBottom quartile

(6 manuals) 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.

    Get a quote

Key ratings

Rated cooling

12,000BTU/h[3]

Rated heating

12,000BTU/h[3]

Best-fit use cases

The right 12k for a standard room in a colder climate, where holding heat through winter is worth the 230V wiring and the premium over the simpler 115V version.

Buyer review snapshot

Best for / skip if

Best for

  • Top efficiency shortlists; SEER2 is 25.5.

Install difficulty

Professional install
  • Electrical: 230V; MCA 12 A; breaker/fuse 15 A.
  • Line set: connection type not sourced; precharged 24.6 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 22, 2026
Source-backed records
6
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

Model context

Structured ratings
Certification: ENERGY STAR certified and AHRI cold-climate designated. Refrigerant: current low-GWP R-454B. Minimum heating ambient: -13 F.

Strengths

  • Genuinely better winter heat than the 115V 12k - more output at 17F and a cold-climate rating to match, so it holds up when it counts.
  • Efficient across both seasons on current low-GWP R-454B refrigerant.
  • Bosch's dealer network and warranty stand behind a premium install.

Weaknesses

  • Needs a dedicated 230V circuit, so wiring is more involved - and can cost more - than the 115V model.
  • Dealer-installed premium equipment: a higher up-front price than DIY value brands, though the warranty and service network offset it over the unit's life.

Climate suitability

Minimum heating ambient
-13 F[1]
Certified heating at 5F
8,400 BTU/h[3]
Rated heating at 17F
10,100 BTU/h[3]
Rated heating at 47F
12,000 BTU/h[3]

Specifications

Show
Manufacturer
Bosch
Brand
Bosch
Product line
Climate 5000 Gen 4
Model number
BMS500-AAU012-1AHWXD indoor / BMS500-AAS012-1CSXRD outdoor
Indoor unit model
BMS500-AAU012-1AHWXD
Outdoor unit model
BMS500-AAS012-1CSXRD
Number of zones
1
Max indoor units
not published
Rated cooling capacity
12,000 BTU/h[3]
Rated heating capacity
12,000 BTU/h[3]
Voltage
230 V[1]
MCA
12 A[1]
Maximum fuse or breaker size
15 A[1]
Breaker needed
not published
SEER2
25.5 SEER2[3]
EER2
13 EER2[3]
HSPF2 (Region 4)
10.6 HSPF2[3]
HSPF2 (Region 5)
not published
COP
not published
COP at 47F
3.9 COP[1]
COP at 5F
2.3 COP[3]
Minimum outdoor heating temperature
-13 F[1]
Minimum outdoor cooling temperature
-13 F[1]
Maximum outdoor temperature
122 F[1]
Indoor noise range
18-46 dB(A)[1]
Outdoor noise rating
56 dBA[1]
Indoor weight
22.93 lb[1]
Outdoor weight
62.17 lb[1]
Refrigerant
R-454B[3]
Refrigerant charge
32.45 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
49.2 ft[1]
Max height between indoor units
not published
Wi-Fi support
not supported[2]
Energy Star status
ENERGY STAR certified[5]
AHRI certification number
215223298[3]
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 215223298, ENERGY STAR exact check 215223298, Climate 5000 Ductless System Mini-Split Heat Pump (R-454B Version), Bosch Climate 5000 ductless mini-split submittal sheet directory, BMS500-AAU012-1AHWXD & BMS500-AAS012-1CSXRD Bosch Climate 5000 Gen 4 R-454B 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
12 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

Show
Liquid line
1/4 in[1]
Suction line
3/8 in[1]
Line connection type
not published
Precharged length
24.6 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
31.42 x 9.21 x 11.85 in[1]
Outdoor dimensions
30.12 x 11.93 x 21.85 in[1]
Indoor weight
22.93 lb[1]
Outdoor weight
62.17 lb[1]
Drain size
not published

Related systems and guides

Frequently asked questions

Can I install the Bosch Climate 5000 Gen 4 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD) myself, or do I need a pro?
Bosch Climate 5000 Gen 4 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD) 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 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD) keep heating in a cold winter?
The AHRI/ENERGY STAR certification lists 8,400 BTU/h of heating capacity at 5F. Rated heating operation extends down to -13 F. Certified heating efficiency is 10.6 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 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD) need?
Published electrical requirements: 230 V voltage, 12 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 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 R-454B 12,000 BTU Regular (BMS500-AAU012-1AHWXD / BMS500-AAS012-1CSXRD) 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-AAU012-1AHWXD & BMS500-AAS012-1CSXRD Bosch Climate 5000 Gen 4 submittalSourced - manufacturer technical document

    Covers Frequency, electrical_spec.indoor_mca_amps, Maximum breaker size, Maximum fuse size, Minimum circuit ampacity, Phase and more

  2. Bosch Thermotechnology Corp.: Air-to-Air R-454B Heat Pump Systems FAQSourced - manufacturer product page

    Covers Wi-Fi support

  3. AHRI Directory: AHRI public directory record 215223298Sourced - AHRI directory

    Covers AHRI certification number, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity, HSPF2 (Region 4) and more

  4. Air-Conditioning, Heating, and Refrigeration Institute: AHRI Appendix M1 public detail for BMS500-AAS012-1CSXRD / BMS500-AAU012-1AHWXDSourced - AHRI directory

    Covers performance_spec.cold_climate_designation, system.lifecycle_status

  5. ENERGY STAR Certified Air-Source Heat Pumps Directory: ENERGY STAR record 3554554 for BMS500-AAS012-1CSXRD / BMS500-AAU012-1AHWXDSourced - Energy Star listing

    Covers Energy Star status

  6. Bosch Thermotechnology Corp.: Climate 5000 Ductless System Mini-Split Heat Pump (R-454B Version) manufacturer 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 22, 2026