Mitsubishi Electric, founded in Japan in 1921, makes ductless heads, compact ducted units and large VRF systems, all built around inverter heat pumps. In Tiburon, Belvedere and Mill Valley we repair, maintain and install them, from a single wall unit in a converted attic to a whole house run on several zones. We are an independent service company and not affiliated with Mitsubishi Electric.
M-Series, P-Series and City Multi
- M-Series is the residential line: wall-mounted, floor-mounted, ceiling cassette and slim ducted indoor units on single-zone or multi-zone outdoor units.
- P-Series covers larger capacities, including ducted air handlers and ceiling units used in big homes and light commercial spaces. A P-Series air handler can take the place of a furnace and run through existing ducts.
- City Multi is Mitsubishi Electric’s VRF system for large buildings and very large homes, with many indoor units on one refrigerant network.
Hyper-Heating INVERTER in a long, damp heating season
Hyper-Heating INVERTER outdoor units are designed to hold their heating output at low outdoor temperatures. Southern Marin rarely sees that kind of cold, but homes on shaded Mill Valley lots and under the redwoods need heat for most of the year. For them the useful part is steady, quiet heating with long low-speed runs instead of a furnace’s on-off cycle. When one of these systems stops heating well, we check defrost operation, the outdoor sensors, the coil and the refrigerant charge.
3D i-see Sensor and controls
Some Mitsubishi Electric wall units carry the 3D i-see Sensor, which reads temperatures across the room, notices where people are and directs airflow accordingly. If a head seems to aim air oddly, the sensor settings on the remote are worth checking before anything else. Wi-Fi control runs through Mitsubishi Electric’s app and a Wi-Fi adapter; a head that drops offline usually needs the adapter reconnected, not a repair.
Ductless in older Mill Valley houses
Homes from the early 1900s to the 1960s leave little room for new equipment: crawlspace ducts that serve part of the house, plaster walls, steep lots. Mitsubishi Electric systems work around that, and planning decides how well:
- Line set and drain routes. We plan where the copper and the condensate line leave each room, and whether a condensate pump is needed where water cannot drain by gravity.
- Head placement. Wall units go where they reach the room without blowing on a bed or a sofa.
- The outdoor unit. It goes where it can be serviced, stays quiet for the neighbours and is clear of leaves and needles.
More on that work: mini-split installation in Mill Valley and mini-split installation.
Common service calls
| What you see | Usual cause |
|---|---|
| Water dripping from a wall head | Clogged drain line or pump, head out of level |
| Musty smell when the head starts | Dirty coil and blower wheel in a damp room |
| Head blinks and will not run | Fault code: sensor, board or communication |
| Outdoor unit iced and not clearing | Defrost control, sensor or low charge |
| One zone weak on a multi-zone unit | That zone’s circuit, sensor or airflow |
Our mini-split repair visits start with the fault code and the drain, and repairs carry a 90-day warranty. If you are replacing a furnace, a ducted unit may fit; see heat pump installation. Local pages: Mitsubishi Electric in Tiburon, Belvedere and Mill Valley.