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LG Multi F MU3R21.U21 Triple-Zone Inverter Condenser 6.2kW
LG

LG Multi F MU3R21.U21 Triple-Zone Inverter Condenser 6.2kW

In StockEnergy A+++
£1,595.000

Trade pricing available — apply or sign in for your trade rate

2-4 working days
UK-Wide Delivery
Free UK mainland delivery on in-stock units

Retail prices include VAT.

Engineered for medium-to-large UK family homes and commercial suites, the LG Multi F MU3R21.U21 accommodates up to three indoor air handlers on a single efficient outdoor plant. Delivering 6.2kW of nominal cooling paired with 7.0kW of rapid heat pump output, it reliably handles high-demand spaces through variable-speed BLDC compressor modulation. Low-GWP R32 refrigerant ensures elevated thermal transfer while meeting European environmental standards, and the unit achieves top-tier A+++ seasonal efficiency metrics. LG’s proprietary Ocean Black Fin technology shields the internal coil from harsh elements, moisture, and road pollutants, guaranteeing durable operation. The triple-zone architecture allows custom configurations of bedroom and ground-floor indoor units, controlled separately using wired wall controllers, handheld remotes, or smartphone connectivity through the LG ThinQ infrastructure. Because proper flare joints, vacuuming, and electrical isolation are crucial, installation must be carried out by certified HVAC engineers. It remains an ideal whole-home heat pump retrofit.

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Smart-home ready

Connects natively with the systems below — control by app or voice.

LG ThinQAmazon AlexaGoogle Assistant
  • Free UK mainland delivery on in-stock units
  • Manufacturer warranty included
  • 14-day returns

Full Specifications

Cooling Capacity21,000 BTU
Recommended Room Size3 rooms (up to 60m² combined)
Energy RatingA+++
Smart HomeLG ThinQ, Amazon Alexa, Google Assistant
Noise Level
CategoryMulti-Split System AC
SKULG-MU3R21-U21

Description

Engineered for medium-to-large UK family homes and commercial suites, the LG Multi F MU3R21.U21 accommodates up to three indoor air handlers on a single efficient outdoor plant. Delivering 6.2kW of nominal cooling paired with 7.0kW of rapid heat pump output, it reliably handles high-demand spaces through variable-speed BLDC compressor modulation. Low-GWP R32 refrigerant ensures elevated thermal transfer while meeting European environmental standards, and the unit achieves top-tier A+++ seasonal efficiency metrics. LG’s proprietary Ocean Black Fin technology shields the internal coil from harsh elements, moisture, and road pollutants, guaranteeing durable operation. The triple-zone architecture allows custom configurations of bedroom and ground-floor indoor units, controlled separately using wired wall controllers, handheld remotes, or smartphone connectivity through the LG ThinQ infrastructure. Because proper flare joints, vacuuming, and electrical isolation are crucial, installation must be carried out by certified HVAC engineers. It remains an ideal whole-home heat pump retrofit.

Winter heating cost: this AC vs electric heaters

This unit reverses to heat your room in winter. Based on its 7 kW heat output used 5 hrs/day over a 150-day UK heating season at £0.27/kWh.

Electric heater / season

£1424

This AC / season

£475

You save / season

£950

~67% less electricity

Heating methodElectricity / seasonCost / seasonEfficiencySummer cooling
This heat-pump AC1758 kWh£475Up to 300%
Plug-in electric heater5275 kWh£1424100%
Electric storage heater5275 kWh£1424100%

Heat output estimated from this unit's 24,000 BTU/hr rating. A heat pump moves heat (COP ≈ 3), so it uses about a third of the electricity of a direct-electric heater for the same warmth. Actual savings vary with room size, insulation, tariff and usage. See the full comparison →