Mitsubishi Heavy Industries air conditioning

Who makes MHI air conditioning

Mitsubishi Heavy Industries is a Japanese engineering group. Its European air conditioning business is Mitsubishi Heavy Industries Air-Conditioning Europe (MHIAE), which describes itself as supplying heating and cooling systems for homes, businesses and industry. In the UK the products are sold through distributors to installers rather than direct to the public.

The most common question we get is whether MHI and Mitsubishi Electric are the same. They are not. Both carry the Mitsubishi name, but they are different companies with different designs, model codes, parts, controllers and fault codes. Before you order a part, a remote or a repair, check the nameplate on the unit: it will say either “Mitsubishi Electric” or “Mitsubishi Heavy Industries”.

Ranges for homes

MHIAE groups its domestic products as single splits and multi-splits (it calls the smaller systems RAC). These are mainly wall-mounted units, with floor-mounted options in some ranges.

A multi-split runs two or more indoor units from one outdoor unit, which is handy for a pair of bedrooms or a bedroom and a home office. We confirm the exact models, sizes and features on your quote after a survey, because ranges and model codes change from year to year.

Ranges for business and larger buildings

For commercial work, MHIAE lists larger single splits and multi-splits (PAC), which pair outdoor units with ceiling cassettes, ducted units and under-ceiling units, and a VRF range for buildings with many zones. These suit offices, shops, restaurants and hotels.

MHIAE also makes air-to-water heat pumps under the Hydrolution name, including Hydrolution EZY versions using R290 and R32, and Q-ton, a CO2 heat pump water heater aimed at commercial hot water. We install air-to-water heat pumps as an MCS certified company: see our air-to-water heat pumps page for how that works.

Refrigerants and controls

Current MHI split systems for UK homes generally use R32, which has a GWP of 675. Older MHI systems may use R410A (GWP 2,088). Both can still be serviced and repaired legally, but R410A is getting scarcer and dearer as the F-gas phase-down tightens. If you have an older system, our guide on repairing or replacing R410A and R22 systems helps you weigh it up.

MHIAE offers local and remote controllers, including wired wall controllers for commercial systems and a Smart M-Air app for phone control on compatible models. Whether your unit can use the app depends on the model and whether a Wi-Fi interface is fitted.

Where MHI fits

• Bedrooms, offices and living rooms: wall-mounted single splits or a multi-split.
• Shops and small offices: cassettes or ducted units on a larger split.
• Multi-zone buildings: VRF with central control.
• Existing MHI sites: where a building already has MHI equipment, staying with the brand can keep controls and spares consistent.

Warranty

Any warranty on an MHI system is the manufacturer’s, supplied through the distributor, and the terms depend on the product and how it was installed and registered. MHIAE’s FAQ advises contacting the original installer or the distributor for product issues. For a new system we explain the manufacturer’s warranty on your quote, and we keep commissioning and service records so any claim is straightforward. We don’t add a warranty of our own.

Diagnosing faults on MHI systems

When an MHI unit stops working properly, the first clue is often a flashing light or a code on the controller. Because MHI codes differ from Mitsubishi Electric’s, the code on its own can mislead if you look it up against the wrong brand. When you contact us, send a photo of the nameplate and the controller display if you can. That lets us check the code against the right documentation and bring the most likely parts.

On the visit we check the basics first: power, filters, the condensate drain and the outdoor unit’s airflow. Then we test the refrigerant circuit, sensors and electronics. We explain what we’ve found in plain terms, give you a fixed price for any repair and tell you honestly if a very old system is worth repairing or ready for replacement. If refrigerant has been lost, we find and fix the leak before topping up, and record the work in the F-Gas records.

Strengths and things to consider

Strengths: a full range from single rooms to VRF and air-to-water heat pumps; long experience in compressors and refrigeration; and a strong presence in commercial buildings.

Things to consider: MHI is less visible to homeowners than some brands, so fewer people compare it; the name confusion with Mitsubishi Electric can lead to wrong parts being ordered; and as with any brand, parts for older or discontinued ranges can take longer to source. We tell you if that’s likely before you commit to a repair.

Installing, servicing and repairing MHI systems

We install new MHI systems and look after existing ones. Domestic prices are the same as for other leading brands: £1,200–£2,200 + VAT for a single-room split and £2,800–£4,500 + VAT for a 2-room multi-split, including supply, installation, commissioning and F-Gas documentation. Commercial and VRF systems are priced after a survey.

For an existing system, an annual service is £95–£150 + VAT, and a repair call-out starts from £75 + VAT for diagnosis. If your unit is flashing a code, tell us the full model number from the label when you get in touch, so we can check the code before we arrive. We reply to enquiries the same working day.