MRCOOL® DIY-MULTI3-18HP230D-O — MRCOOL DIY 5th Generation 3-Zone Heat Pump System, 3× 6,000 BTU wall-mount Air Handlers, 18,000 BTU Condenser, R-454B, 208/230V

MRCOOL DIY 5th Generation 3-zone multi-zone system — matched condenser and air handlers, pre-paired

One order, one matched system. This is a complete 3-zone MRCOOL DIY 5th Generation heat pump: the DIY-MULTI3-18HP230D-O outdoor condenser paired with 3 × DIY-06-HP-WMAH-230D25-O indoor air handlers, in a combination MRCOOL’s published matchup table lists as valid for this condenser. There is nothing to cross-reference and no risk of ordering an air handler that will not run on the outdoor unit.

What’s included

• 1 × DIY-MULTI3-18HP230D-O — 3-port outdoor inverter condenser, 18,000 BTU/h nominal cooling
• 3 × DIY-06-HP-WMAH-230D25-O — 6,000 BTU/h wall-mount indoor air handler

MRCOOL published kit DIYM318HPW00D15 uses this exact combination.

System specifications

Outdoor condenser

Indoor air handlers

Port assignment: MRCOOL requires the largest-capacity air handler to be connected to the A port. All air handlers in this system are the same capacity, so any port order is acceptable.

Line sets are not included

Multi-zone line set lengths differ for every zone, so forcing a single length into the box would waste material on short runs and fall short on long ones. Choose the lengths you need from the R-454B line sets listed below. The condenser’s refrigerant connections are liquid 1/4″ and suction 3/8″, and factory charge covers 24.6 ft per zone — longer runs need additional refrigerant added at commissioning.

Installation

• DIY series — the pre-charged quick-connect line sets are designed to be joined without brazing, vacuum pump or gauges.
• R-454B is a mildly flammable A2L refrigerant. Follow current local code for A2L equipment, including any charge-limit and ventilation requirements for the space served.
• A dedicated 208/230V circuit is required, sized to the MCA and maximum fuse rating above.
• Electrical work and refrigerant handling must comply with local code. Permits may be required in your jurisdiction.

Warranty

5-year parts and 7-year compressor limited warranty. Registering the system and enrolling in MRCOOL Care extends coverage to a Limited Lifetime Replacement warranty. Register within the period MRCOOL specifies to keep full coverage.

Why buy this as a set

• The condenser and air handlers are a combination MRCOOL itself lists — no guesswork.
• Every component ships on the same order, so you are not waiting on a mismatched part.
• All components use R-454B, the refrigerant that replaced R-410A, so the system is not on a phase-out path.