MXZ & MSZ not putting out heat.
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 advice.
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Replies
bump.
https://www.theacoutlet.com/documents/Owners-Manual-Mitsubishi-MXZ2C.pdf
too much for me to parse, but section 11-6 references cool/no heat
Are you sure it does not work? Turn it on, set it to heat mode on the remote and crank it up as high as it will go.
When switching from cold to hot there is a significant delay before heat is produced[on single units]
Even after almost 20 years of dealing with them, even switching to a new brand it is non obvious how some features work
Doesn't sound right. My folks have the 2c24 version and it heats/cools without issues.
Here is the full documentation for the unit:
https://mylinkdrive.com/USA/M_Series/R410A_Systems-3/Outdoor_Equipment/R410A_Outdoor/MXZ_3C30NA2_U1?product&categoryName=R410A_Outdoor
I don't think you can disable heat on these but I haven't dug into the manuals in that much detail. Both heads have to be set to the same mode though, so check that first.