MrCool DIY 5th Gen 27K Multi-Zone Condenser (4 zones)

Model DIY-MULTI4-27HP230D-O

SCORE6.3 / 10

Up to four heads and 18,200 Btu/h at 5°F, enough for a typical bedroom floor. Condenser only on Amazon; buy matching 5th Gen heads separately.

View on Amazon →Read our full review

Specs

Spec	MrCool DIY 5th Gen 27K Multi-Zone Condenser (4 zones)
Nominal size	27,000 BTU
Voltage	230V
Rated heat at 47°F	26,000 BTU/h
Heat at 17°F	16,200 BTU/h
Heat at 5°F	18,200 BTU/h
Lowest heating temp	-13°F
Max heat at lowest temp	9,700 BTU/h
SEER2	23
HSPF2 (Region IV)	9
Install type	Quick-connect
Line set in box	25 ft
Max line run	75 ft
Warranty covers owner install	Yes
Warranty, parts	5 yr
Warranty, compressor	7 yr
ENERGY STAR Cold Climate	Yes
ENERGY STAR	Yes
Refrigerant	R-454B
Zones	Up to 4 indoor units
Minimum heat output at 47°F	8,400 Btu/h (whole system)
Electrical	208/230V; 23 A MCA, 25 A max breaker
Line limits	75 ft per head, 221 ft total, 33 ft height indoor to outdoor

Sources: NEEP ccASHP list · MRCOOL DIY 5th Gen multi-zone install manual · MRCOOL DIY 5th Gen multi-zone service manual (Apr 20, 2026) · MRCOOL DIY 5th Gen limited warranty (rev. 07.03.25)

Before you buy

The 4th Gen multi-zone (C suffix, R-410A) is a different system; its 18K ran two zones, not three.
On earlier generations owners report idle heads still heating or cooling and rooms overshooting setpoint; there is no long 5th Gen record yet.
Line sets are one-time installs; runs past the standard 24.6 ft per head and ducted (AHU) air handlers call for added refrigerant per the manual.
Sold on Amazon by a third-party seller in small quantities; condenser only, heads and line sets sold separately.
NEEP lists its 17°F rating (16,200) below its 5°F rating (18,200).

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Where we cover it

MrCool DIY Multi-Zone Review: One Condenser, Many Rooms, Real Catches