Re my Convair Supercool: Fan is functioning but doesnt cool or heat. Can it be that the gas needs recharging?

How do I tell for sure whether the compressor is coming on? The noise? After running the machine for two or three minutes in cool mode with only fan noise, another noise comes in which sounds to me like it could be the compressor. How do I tell for sure whether the compressor is coming on? The noise? After running the machine for two or three minutes in cool mode with only fan noise, another noise comes in which sounds to me like it could be the compressor.

If you can gain access to the evaporator coil or the suction or discharge line to the compressor you will be able to tell immediately when the compressor starts. The suction line (larger of the two) will be cold and the discharge (smaller of the two) will be warm to the touch. If you cannot gain access and don't want to tear into the unit simply see if cold air initially flows from the evaporator coil into your room. If it does initially and stops your compressor is starting, but shutting off on overload. This could be an electrical problem or a situation in which there is a leak and the compressor is therefore not being cooled sufficiently. Most compressors have a temperature sensitive shutoff to protect the compressor if it is not being cooled sufficiently by refrigerant gas. A low charge (leak) will cause this to occur. You may have to open the unit up and investigate to find the answer you are seeking. Hope this helps. If you can gain access to the evaporator coil or the suction or discharge line to the compressor you will be able to tell immediately when the compressor starts. The suction line (larger of the two) will be cold and the discharge (smaller of the two) will be warm to the touch. If you cannot gain access and don't want to tear into the unit simply see if cold air initially flows from the evaporator coil into your room. If it does initially and stops your compressor is starting, but shutting off on overload. This could be an electrical problem or a situation in which there is a leak and the compressor is therefore not being cooled sufficiently. Most compressors have a temperature sensitive shutoff to protect the compressor if it is not being cooled sufficiently by refrigerant gas. A low charge (leak) will cause this to occur. You may have to open the unit up and investigate to find the answer you are seeking. Hope this helps.