serin labs
Multi-Zone Controller · Whole-system control In development
Every zone of your system, in one place.
The Multi-Zone Controller joins your Mitsubishi multi-zone system's communication wire and brings the whole installation into your smart home platform. Every indoor unit as its own climate accessory, plus the telemetry that only the pros see.
Reservable now. We will email you when ordering opens.
Reserve yoursBefore you reserve
Will it work with your system?
City Multi, PUMY and M-series with a branch box do. Check by the model number on the outdoor unit’s label, not the indoor unit’s.
CITY MULTI
VRF systems, including branch controllers. Wire in at the outdoor unit, at a branch controller, or at any supported indoor unit. Scales from a single outdoor unit to large installations with multiple outdoor units on the same bus.
PUMY / P-series
Light-commercial systems on the same two-wire transmission bus. Wire in at the outdoor unit's terminals.
M-series with a branch box
Branch box systems only. Wire in at the outdoor unit or the branch box. Ported outdoor units, where each head runs its own refrigerant lines back to the outdoor unit (i.e. MXZ-4C36NA), are not supported.
Single-zone unit? The Serin Controller is the right device. Not sure which system you have, or running an unusual mix such as City Multi indoor units on an M-series outdoor unit? Ask us: a model number is enough.
How it connects
One connection covers every zone.
The Multi-Zone Controller wires to the communication wire at your outdoor unit or branch box. On City Multi you can also land it at an indoor unit, whichever is easiest to reach. It draws its power from that pair, so there is no wall adapter and no extra wiring. One device covers the whole system.
Multi-Zone Controller
Outdoor unit or branch box
Indoor units, every zone
Multi-Zone Controller
Outdoor unit or branch box
Indoor units, every zone
Control
Control every indoor unit.
Every indoor unit on the system appears in your smart home platform as its own thermostat: power, mode, fan speed, and setpoint, per zone. Change one room without touching the others, automate them independently, and see each zone's live state come back from the equipment itself.
There is also a built-in web UI on your network for setup and a live view of the whole system, no Home Assistant required.
Telemetry
See what your system is actually doing.
Your outdoor unit tracks refrigerant pressures, valve positions, compressor current, and a dozen temperatures. These are readings that normally require a service visit to see. The Multi-Zone Controller reads them live and publishes every one to your smart home platform as its own entity.
HIGH-SIDE
208.4 psi
COMPRESSOR
58 Hz
ZONES CALLING
3 of 5
SUPERHEAT
8.6 °F
SUBCOOL
11.2 °F
- discharge + suction pressure
- LEV pulses, per branch
- superheat + subcool
- operating frequency
- compressor current
- fan step
- th1 / th2 / th3, per indoor unit
- discharge temperature
- room + setpoint, per zone
- mode · run/stop, per zone
- reversing valve + solenoids
- fault codes, decoded
Sensor set varies by outdoor unit model. Values shown are illustrative.
Tech specs
The hardware inside.
Enclosure, dimensions, and final connector layout are published when the production run is final.
Good to know
Frequently asked questions.
Does it replace my remotes or central controller?
No. It joins the transmission bus alongside them. Your existing wall controllers, remotes, and any central controller keep working, and the Multi-Zone Controller shows their changes live.
Does it need Wi-Fi?
Yes: that is how it reaches your smart home platform and its own web UI. Everything stays on your network: no cloud, no account.
How is this different from the Serin Controller?
They take different views of the same system. The Serin Controller plugs into an indoor unit's CN105 port, one controller per unit. The Multi-Zone Controller connects once to the system's communication wire and covers every zone with a single device, plus system-level telemetry the CN105 port does not carry.
Is installation invasive?
Two wires to the transmission-bus terminals, the pair the rest of the system already runs on. That is the outdoor unit or the branch box, and on City Multi an indoor unit as well. The bus also powers the device. Power the system down before opening anything.
Will it work with the Serin Link?
Pairing with the Serin Link is planned: one knob on your shelf, every zone of the system behind it. Reserve either and we will keep you posted.
Can I request features?
Yes, please. The Multi-Zone Controller is in active development and feedback shapes it: tell us your system and what you want from it when you reserve.
In development
Reserve one from the first production run.
Tell us your system and what you would want from it: it will influence what ships, and you will be first in line when ordering opens.