Service & test modes: Mini-Split tips

Short, practical technician tips on service & test modes for mini-split. Check each one against the manual for your exact model before acting.

Read live data with the outdoor check button (SW1)

Carrier · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

Each press of SW1 steps through a value on the outdoor display.

1. Press 1 = number of indoor units talking. 2 = mode (0 off, 1 fan, 2 cool, 3 heat, 4 forced cool, A forced defrost).
2. Presses 17-21 = T2B per zone, 22-26 = room temp per zone, 27-31 = coil temp per zone, 32 = T3, 33 = T4, 34 = discharge temp.
3. Press 45 (all sizes) = last fault or protection (00 = none). See the check switch table for the full list; the 18K board uses a slightly different order.

Run the automatic wiring / piping correction

Carrier · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

The outdoor unit can find and fix crossed wiring vs piping ports by itself.

1. Outdoor temperature must be above 41 F (5 C). Indoor units do not need to be running.
2. Hold CHECK (SW1) on the outdoor board about 6 seconds until CE shows (FA may show first, keep holding).
3. Indoor units go to 76 and the compressor runs for about 5-10 minutes.
4. When CE changes to 00 it is done. Set each indoor unit back with its remote (they stay at 76).

Read live data with the outdoor check button (SW1)

Midea · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

Each press of SW1 steps through a value on the outdoor display.

1. Press 1 = number of indoor units talking. 2 = mode (0 off, 1 fan, 2 cool, 3 heat, 4 forced cool, A forced defrost).
2. Presses 17-21 = T2B per zone, 22-26 = room temp per zone, 27-31 = coil temp per zone, 32 = T3, 33 = T4, 34 = discharge temp.
3. Press 45 (all sizes) = last fault or protection (00 = none). See the check switch table for the full list; the 18K board uses a slightly different order.

Run the automatic wiring / piping correction

Midea · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

The outdoor unit can find and fix crossed wiring vs piping ports by itself.

1. Outdoor temperature must be above 41 F (5 C). Indoor units do not need to be running.
2. Hold CHECK (SW1) on the outdoor board about 6 seconds until CE shows (FA may show first, keep holding).
3. Indoor units go to 76 and the compressor runs for about 5-10 minutes.
4. When CE changes to 00 it is done. Set each indoor unit back with its remote (they stay at 76).

Read live data with the outdoor check button (SW1)

Viessmann · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

Each press of SW1 steps through a value on the outdoor display.

1. Press 1 = number of indoor units talking. 2 = mode (0 off, 1 fan, 2 cool, 3 heat, 4 forced cool, A forced defrost).
2. Presses 17-21 = T2B per zone, 22-26 = room temp per zone, 27-31 = coil temp per zone, 32 = T3, 33 = T4, 34 = discharge temp.
3. Press 45 (all sizes) = last fault or protection (00 = none). See the check switch table for the full list; the 18K board uses a slightly different order.

Run the automatic wiring / piping correction

Viessmann · DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

The outdoor unit can find and fix crossed wiring vs piping ports by itself.

1. Outdoor temperature must be above 41 F (5 C). Indoor units do not need to be running.
2. Hold CHECK (SW1) on the outdoor board about 6 seconds until CE shows (FA may show first, keep holding).
3. Indoor units go to 76 and the compressor runs for about 5-10 minutes.
4. When CE changes to 00 it is done. Set each indoor unit back with its remote (they stay at 76).