Brand new Midea heatpump non-ducted multi-head not working as desired.

A homeowner in rural northwest British Columbia installed a new Midea multi-zone heat pump system this fall: a 5-ton outdoor unit paired with five indoor heads (one 24,000 BTU, one 12,000 BTU, and three 6,000 BTU units) covering a 2,600-square-foot, two-story house. Instead of holding a steady temperature, the system overshoots the target, then blows noticeably cooler air at low fan speed for 10 to 15 minutes before heating again, causing repeated temperature swings in each room. Lowering the fan speed did not fix it. The homeowner installed the system quickly to catch a provincial rebate that cut the cost to $1,900 out of pocket, but is now struggling to get help, since the original installer seems hard to reach and other local tradespeople have month-long waits.

A commenter with building science experience said this pattern is common with multi-head heat pump systems when they are oversized for the current mild weather, or oversized for the house generally. With light heating loads, the compressor sometimes cannot slow down enough to match what a single zone needs, so it cycles on and off rather than running steadily. The commenter suggested measuring actual air and room temperatures during both the heating and "resting" phases, rather than judging by feel, since moving air can seem cooler than it is. That data would help pin down whether the issue is oversizing, control settings, or something else.

If you are weighing a heat pump install yourself, this is a reminder that right-sizing the equipment to the home, not just claiming the rebate, matters for comfort.