MRCOOL 5th Gen DIY® Multi-Zone Heat Pump: Specs, Features & Builder Guide
The 5th Gen MRCOOL DIY® Multi-Zone Series brings higher efficiency, smarter controls, and support for up to six zones—all while keeping true DIY installation intact with Quick Connect lines. Use this guide to compare models, confirm coverage, and start building a system that fits your home.
Build Your Multi-Zone System • Hybrid (Central + Mini-Split) Builder • Step-by-Step Install Video
Note: 5th Gen systems use R-454B refrigerant and include updated efficiency ratings (SEER2/HSPF2). Now available with ENERGY STAR® and Cold Climate qualifications on select models. [See brochure details]
What’s New in 5th Gen DIY® Multi-Zone
- Up to 6 indoor zones from a single condenser (new max).
- R-454B refrigerant (next-gen, lower GWP).
- ENERGY STAR® V6.1 and Cold Climate availability; eligibility for federal tax credits, NEEP, CEE tiers, and MASS Save on select models.
- DIY-friendly upgrades: Quick Connect®, DIYPRO® Armored Cable, Smartphone App + Alexa/Google, Gold Fin® corrosion resistance, Leakage Detection, Follow Me® comfort, and Auto Restart.
Quick Specs by Condenser
The table below summarizes capacity, zones, efficiencies, coverage, and electrical for each multi-zone condenser in the 5th Gen lineup.
| Model | Max Zones | Cooling (Btu/h) | Heating (Btu/h) | SEER2 | HSPF2-4 / -5 | Coverage (sq ft) | Sound dB(A) | Power / MCA / Max Fuse | Refrigerant | Piping (Liquid/Gas) |
|---|---|---|---|---|---|---|---|---|---|---|
| DIY-MULTI3-18HP230D-O | 3 | 18,000 | 18,000 | 23.9 | 10.0 / 7.8 | Up to 750 | 60 | 208–230V 1Ph / 16A / 20A | R-454B | 1/4" – 3/8" |
| DIY-MULTI4-27HP230D-O | 4 | 26,000 | 26,000 | 23.0 | 9.5 / 7.0 | Up to 1,125 | 61 | 208–230V 1Ph / 23A / 25A | R-454B | 1/4" – 3/8" |
| DIY-MULTI5-36HP230D-O | 5 | 34,000 | 36,000 | 23.0 | 9.9 / 7.5 | Up to 1,500 | 64 | 208–230V 1Ph / 30.5A / 35A | R-454B | 1/4" – 1/2" |
| DIY-MULTI6-48HP230D-O | 6 | 43,000 | 48,000 | 21.8 | 10.0 / 7.8 | Up to 2,000 | 64 | 208–230V 1Ph / 40A / 45A | R-454B | 1/4" – 1/2" |
| DIY-MULTI6-55HP230D-O | 6 | 47,000 | 55,000 | 22.0 | 10.6 / 8.5 | Up to 2,290 | 64 | 208–230V 1Ph / 43A / 45A | R-454B | 1/4" – 1/2" |
All values above are from the 5th Gen Multi-Zone brochure spec tables (pages 2–3). Program eligibility (ENERGY STAR®/Cold Climate, tax credits, NEEP, CEE, MASS Save) is noted in those tables and varies by model.
Feature Highlights (Comfort & DIY)
- Quick Connect® Lines – DIY install without vacuum pump or gauges.
- DIYPRO® Armored Cable – Integrated, conduit-free electrical solution.
- Smartphone App + Smart HVAC Controller® – App control and native Alexa/Google support.
- Gold Fin® Condenser – Corrosion resistance for coastal installs.
- Leakage Detection & Auto Restart – Protection and peace of mind.
- Follow Me® – Remote tracks room-side temperature for precise comfort.
Get the Right Matchups & Sizing
Air handlers and condensers should match in size and refrigerant for best performance. Build and validate your configuration with our tools:
- Multi-Zone Builder — choose capacities, room counts, and line lengths.
- Hybrid Builder (Central + Mini-Split) — pair a 2–3 ton central ducted air handler with 1–3 wall or ceiling units.
- DIY Install Video Guide — step-by-step walkthrough from unboxing to first cool/heat.