SplitAtlas

TOSOT / Multi Ultra Heat

TOSOT Multi Ultra Heat 42k R-32 208/230V 5-Zone Mini-Split

Certified capacity
42,000 BTU/h[2]
SEER2
21 SEER2[2]
Heating floor
-22 F[1]
Voltage
230 V[1]
Install path
Professional install

The TOSOT Multi Ultra Heat 5-zone 42k covers five rooms from one 208/230V outdoor unit on R-32, ENERGY STAR certified and AHRI cold-climate designated, at a certified nominal SEER2 of 21 (EER2 13, HSPF2 10). That nominal is the all-non-ducted certified figure and depends on the heads you attach.

Its certified heating is notably strong in the cold - rated 42000 BTU at 47F, 44500 at 17F, and 37800 at 5F, holding high output through the mid-cold range before tapering at 5F. TOSOT is a value brand (TOSOT/Gree family) sold on tosot.com, professionally installed and priced by quote.

5 zonesProfessional installCurrent

Refrigerant generation

R-32 - current-generation refrigerant

Need this installed?

Get installation quotes
Error Codes
TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO)

Image: TOSOT

Data completeness: 97%
Last sourced
Jul 29, 2026

SplitAtlas score

9.0 / 10

Methodology
Cooling efficiencyAbove average

(21.0 SEER2) among >36k systems

Heating efficiencyTop 10%

(10.0 HSPF2) among >36k systems

Cold-weather performanceAbove average

(90% heat retained at 5F; -22 F heating floor) among >36k systems

WarrantyAbove average

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

Feature setBelow average

(4 verified features) across the catalogue

Documentation & partsTop quartile

(7 manuals; spec sheet; 14 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.

    Get a quote

Key ratings

Rated cooling

42,000BTU/hNon-Ducted Indoor Units[2]

Rated heating

42,000BTU/hNon-Ducted Indoor Units[2]

Buyer review snapshot

Best for / skip if

Best for

  • 5-zone projects in the 42k outdoor capacity class.

Install difficulty

Complex professional install
  • Electrical: 230V; MCA 30 A; breaker/fuse 45 A.
  • Line set: connection type not sourced; precharged 164 ft; max 328 ft.
  • 5-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. These TOSOT/Cosmo multi-zone systems are professional-install equipment, so we link to contractor quotes rather than a retail price.

Source date

Model data sourced
Jul 29, 2026
Page reviewed
Jul 29, 2026
Source-backed records
5
Newest source retrieved
Jul 29, 2026

Warranty tiers

Warranty: 10 years parts and compressor as standard.

Review methodology

Model context

Install path
This is professional-install equipment; no verified current retail offer is attached.
Structured ratings
Certification: ENERGY STAR certified, ENERGY STAR cold-climate certified and AHRI cold-climate designated. Refrigerant: current low-GWP R-32. Minimum heating ambient: -22 F.

Strengths

  • Five zones from one outdoor unit with strong certified cold-weather heat (44500 BTU rated at 17F, 37800 at 5F).
  • Certified SEER2 21 / EER2 13 / HSPF2 10, ENERGY STAR certified and cold-climate designated on R-32.
  • One 208/230V circuit for five rooms at a value price.

Weaknesses

  • Five-zone total capacity is shared; size to the condenser, not five full rooms.
  • Value-brand dealer/service network is thinner than the majors'.

Climate suitability

Minimum heating ambient
-22 F[1]
Rated heating at 5F
37,800 BTU/hNon-Ducted Indoor Units[2]
Rated heating at 17F
44,500 BTU/hNon-Ducted Indoor Units[2]
Rated heating at 47F
42,000 BTU/hNon-Ducted Indoor Units[2]

Specifications

Show
Manufacturer
TOSOT
Brand
TOSOT
Product line
Multi Ultra Heat
Model number
TMH42D32MO
Indoor unit model
Indoor heads are selected separately on a multi-zone system
Outdoor unit model
TMH42D32MO
Number of zones
5
Max indoor units
5 units[1]
Rated cooling capacity
42,000 BTU/hNon-Ducted Indoor Units[2]
Rated heating capacity
42,000 BTU/hNon-Ducted Indoor Units[2]
Voltage
230 V[1]
MCA
30 A[1]
Maximum fuse or breaker size
45 A[1]
Breaker needed
not published
SEER2
21 SEER2Non-Ducted Indoor Units[2]
EER2
13 EER2Non-Ducted Indoor Units[2]
HSPF2 (Region 4)
10 HSPF2Non-Ducted Indoor Units[2]
HSPF2 (Region 5)
Certified per indoor-unit combination, not per outdoor unit
COP
not published
COP at 47F
3.9 COP[1]
COP at 5F
2.1 COPNon-Ducted Indoor Units[2]
Minimum outdoor heating temperature
-22 F[1]
Minimum outdoor cooling temperature
-22 F[1]
Maximum outdoor temperature
118 F[1]
Indoor noise range
Indoor heads are selected separately on a multi-zone system
Outdoor noise rating
54 dBA[1]
Indoor weight
Indoor heads are selected separately on a multi-zone system
Outdoor weight
174 lb[1]
Refrigerant
R-32[2]
Refrigerant charge
95.24 oz[1]
Manufacturer coverage
not published
Line-set size
1/4 in x 5 liquid / 3/8 in x 5 suction
Included line-set length
Indoor heads are selected separately on a multi-zone system
Maximum line-set length
328 ft[1]
Max line set per indoor
82 ft[1]
Maximum elevation difference
82 ft[1]
Max height between indoor units
82 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
217994515Non-Ducted Indoor Units[2]
Warranty
Standard: 10 yr parts / 10 yr compressor (equipment sold and installed by licensed professionals in residential applications). TOSOT warranty information lists a standard 10-year compressor warranty and 10-year parts warranty for equipment sold and installed by licensed professionals in residential applications.
Install path
Professional install
Retail price
These TOSOT/Cosmo multi-zone systems are professional-install equipment, so we link to contractor quotes rather than a retail price.
Available retailers
not published
Manual links
AHRI public detail 217994515, ENERGY STAR exact AHRI rows 217994515, TMH42D32MO TOSOT Multi Ultra Heat submittal and official indoor submittals, TOSOT Multi Ultra Heat / TMH42D32MO current product page, Lead-gen/no-retail audit for TMH42D32MO, TMH42D32MO TOSOT Multi Ultra Heat submittal, TOSOT warranty information
Specification sheet
TMH42D32MO TOSOT Multi Ultra Heat submittal
Last sourced date
Jul 29, 2026

Compatible indoor units

This is an outdoor unit. You choose its indoor heads separately - up to the maximum this condenser supports - and you can mix room sizes and styles across the zones. The models below are the heads this unit is documented to pair with.

  • Ceiling cassette air handlers

    9k, 12k, 18k, 24k

    Model numbers
    • 9k: TKH09D32AI
    • 9k: TLH09D32AI
    • 12k: TKH12D32AI
    • 12k: TLH12D32AI
    • 18k: TKH18D32AI
    • 18k: TLH18D32AI
    • 24k: TKH24D32AI

  • Ducted concealed air handlers

    9k, 12k, 18k, 24k

    Model numbers
    • 9k: TFH09D32AI
    • 12k: TFH12D32AI
    • 18k: TFH18D32AI
    • 24k: TFH24D32AI

  • Ducted multi-position air handlers

    12k, 18k, 24k

    Model numbers
    • 12k: TAH12D32AI
    • 18k: TAH18D32AI
    • 24k: TAH24D32AI

  • Floor console air handlers

    9k, 12k, 18k

    Model numbers
    • 9k: TEH09D32AI
    • 12k: TEH12D32AI
    • 18k: TEH18D32AI

  • Wall-mounted air handlers

    7k, 9k, 12k, 18k, 24k

    Model numbers
    • 7k: TWH07CD32AI
    • 9k: TWH09CD32AI
    • 9k: TWH09KD32AI
    • 9k: TWH09PD32AI
    • 12k: TWH12CD32AI
    • 12k: TWH12KD32AI
    • 12k: TWH12PD32AI
    • 18k: TWH18CD32AI
    • 18k: TWH18KD32AI
    • 18k: TWH18PD32AI
    • 24k: TWH24CD32AI
    • 24k: TWH24KD32AI
    • 24k: TWH24PD32AI

Sizing note: do not just add up the rooms. Multi-zone condensers have a maximum total connected capacity, and connecting more head capacity than the unit is rated for is a common installer mistake that hurts efficiency and comfort. Match total head capacity to the condenser's rating.

Electrical requirements

Show
Voltage
230 V[1]
Voltage range
208/230V[1]
Phase
1[1]
Frequency
60 Hz[1]
MCA
30 A[1]
Breaker needed
not published
Maximum breaker size
45 A[1]
Maximum fuse size
45 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 x 5[1]
Suction line
3/8 in x 5[1]
Line connection type
not published
Precharged length
164 ft[1]
Included line-set length
Indoor heads are selected separately on a multi-zone system
Maximum line-set length
328 ft[1]
Max line set per indoor
82 ft[1]
Max height between indoor units
82 ft[1]
Indoor dimensions
Indoor heads are selected separately on a multi-zone system
Outdoor dimensions
40-5/32 x 16-52/64 x 32-33/64 in[1]
Indoor weight
Indoor heads are selected separately on a multi-zone system
Outdoor weight
174 lb[1]
Drain size
not published

Related systems and guides

Frequently asked questions

Can I install the TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO) myself, or do I need a pro?
TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO) 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 TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO) keep heating in a cold winter?
The manufacturer publishes 37,800 BTU/h of heating output at 5F. Rated heating operation extends down to -22 F. Certified heating efficiency is 10 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 TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO) need?
Published electrical requirements: 230 V voltage, 30 A minimum circuit ampacity, and 45 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 328 ft, and the included line set comes pre-charged for 164 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 TOSOT Multi Ultra Heat 5-Zone 42,000 BTU R-32 208/230V (TMH42D32MO) carry?
The manufacturer publishes these warranty tiers: Standard: 10 yr parts / 10 yr compressor (equipment sold and installed by licensed professionals in residential applications). Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.

Data sources

Show
  1. TOSOT: TMH42D32MO TOSOT Multi Ultra Heat submittalSourced - manufacturer technical document

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

  2. AHRI certificate #217994515 - search the AHRI DirectorySourced - 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 215735288Sourced - Energy Star listing

    Covers performance_spec.energy_star_cold_climate, Energy Star status

  4. TOSOT: TOSOT Multi Ultra Heat / TMH60D32MO current product evidenceSourced - manufacturer product page

    Covers product_line.name

  5. TOSOT: TOSOT warranty informationSourced - manufacturer product page

    Covers Legacy compressor warranty value, Legacy warranty value, Standard compressor warranty, Standard warranty conditions, Standard parts warranty, Warranty notes

  6. TMH42D32MO TOSOT Multi Ultra Heat submittal and official indoor submittalsSourced - manual

    Covers Manual links

Last updated

Jul 29, 2026