TradeAssistIQHome

Midea M-Thermal Arctic HT R290 Mono fault HD

Communication fault between master unit and slave unit

Heat pump

What it means

Communication fault between master unit and slave unit. Triggered when, for a cascade system, the communication failure between master unit and slave unit lasts 2 minutes and above.

Likely causes

  1. Communication cables between port H1H2E1 disconnected or misconnected
  2. Dip switch S3-1/2/3 incorrectly set or duplicated address across units
  3. Time difference of providing power supply for master unit and slave unit is greater than 1 min
  4. Faulty Main Control PCB

Where to start

  1. Check communication cables between port H1H2E1 for disconnection or miswiring
  2. Confirm Dip switch S3-1/2/3 of each unit are all correct and not repeated
  3. Check time difference of providing power supply between master unit and slave unit

The full answer, free

  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 106), right under the answer
Ask about HD freeCreate a free account

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Midea manual for the M-Thermal Arctic HT R290 Mono. Check the model on the data plate before you order parts.

Other Midea M-Thermal Arctic HT R290 Mono fault codes