Inverter AC repair

How an inverter AC works

A fixed speed AC runs its compressor at full speed and switches it on and off to hold the temperature. An inverter AC slows the compressor down as the room cools and keeps it running gently. That saves power, but it needs an inverter board, several temperature sensors, and a compressor built for variable speed.

The board watches voltage, current and temperatures. When something is out of range, it stops the outdoor unit to protect itself and often shows a code or blinks a light on the indoor unit. The code helps the technician, but it is a starting point, not a diagnosis. For more on the difference, read inverter vs non-inverter AC.

What you can safely check first

• Note any code on the display or the pattern of blinking lights, and tell us when you book
• Switch the AC off at the MCB for a few minutes, then on again, to reset the board once
• Check the filters and clear the space around the outdoor unit
• If the lights in your home dim or flicker, the voltage may be low, which can stop the outdoor unit
• Do not open the outdoor unit. The board can hold a charge even after the power is off

Common causes we find

• Inverter board fault, often after a voltage surge or from heat and moisture
• Temperature sensors on the coils or pipes giving wrong readings
• Loose or corroded connections in the outdoor unit
• Outdoor fan motor fault, which makes the board shut down on high temperature
• Low gas from a leak
• Communication fault between the indoor and outdoor units

What the technician does

The technician checks the supply voltage, the cable between the units, the sensors and the board. Many board faults can be repaired at component level. Where a repair is not practical, a replacement board is quoted for your model. You hear the price before any work starts.