A friend in the Pac NW (4c) bought a house a few years ago with a Mitsubishi multi-split. The older couple they bought the house from told them that the system is air conditioning only.

Looking up the equipment, MXZ-3C30NA2-U1 and (2x) MSZ-GL15NA-U1, the system should heat and cool – but it doesn’t. I’m guessing that the problem is operator or installer-related and not the fault of the equipment. Is there an installer setting that enables or disables the heating? Are there dip switches that set this? The only thermostats are the little remote controls that came with the heads – there is no wired control.

(https://ashp.neep.org/#!/product/29040/7/25000/95/7500/0///0)

Thanks in advance for your – warming – advice.