How to tell if my air conditioner is low on refrigerant

Refrigerant is the life blood of an air conditioner. It is an indisputable fact that if your system does not have enough refrigerant it will not be able to cool your property.

If your system was properly installed and does not experience a failure in the integrity of the refrigerant lines or other system components it should never have low refrigerant.

Refrigerant in your air conditioning unit is not normally a serviceable item. If your air conditioner has low refrigerant - it probably has a refrigerant leak that needs rectifying before any more refrigerant is added to the system.

What are the symptoms of an air conditioner low on refrigerant

Unless your air conditioner has stopped working altogether there are some symptoms you can look for that are indicators of low refrigerant levels in your air conditioner.

Here are some of the common signs of an air conditioner low on refrigerant

  1. It takes your AC a long time to cool your roomIf the time it takes your air conditioner to cool your room \ house is taking longer and longer it could indicate a problem with the level of the refrigernat charge in your ac. A similar indicator would be if your air conditioner seems to cope ok on milder days or at night - but struggles during the heat of the day.
  2. The indoor unit of your Air Con is not blowing cool airWhen an air conditioning system is working well, the air coming out of the air vents should feel cold. Typically we would expect an air conditioner to be blowing out air that is at least 10 degrees Celcius cooler than the ambient air. If this is not the case then it indicates the refrigeration cycle in the system is not working properly - a key, but not sole, cause of which is a low refrigerant charge.
  3. There is frost on the refrigerant lines \ pipeworkIf you notice that the refrigerant line to your system is covered in ice this could indicate a low refrigerant charge. Low refrigerant levels, lead to low pressure, which can in turn lead to ice forming on the refrigerant line or indoor coil - called the evaporator.A tell tale sign of an ice buildup on your evaporator coil is water leaking out of your indoor unit - this happens when the ice melts.There are other reasons for your evaporator coil to ice up - most notably poor air flow - which is most often caused by blocked air filters - which are addressed in a regular service regime.
frost on the refrigerant lines
  1. You can hear a hissing \ bubbling sound when your ac unit is runningIf you have a big refrigerant leak and there is still refrigerant in the system you may actually hear the refrigerant escaping when the system is operating - this situation does not normally persist for very long - and the air conditioner will then be out of gas.
  2. Your air conditioning system is short cycling'Short cycling' is a situation where your air conditioner is not cooling effectively, and runs for a while, stops, then runs again. This can be the case when the system is low on refrigerant.
  3. You have seen an increase in your power billsIf your electric bills are rising, even though the air conditioner unit is running and cooling, it can indicate a refrigerant problem. Even if it is running you should see if the air coming out of the air conditioner is cool but not cold - see point 2. above.

How is low refrigerant diagnosed in an air conditioning system?

Ultimately you will need an air conditioning \ HVAC technician to properly diagnose a refrigerant leak in your ac system.

He will confirm the presence of a leak by going to the outdoor unit system and use his gauges to determine the pressure of the gas charge - and whether it is within normal expectations. If it is low - he may even remove the refrigerant and weigh it to determine the amount gas and compare that to the required refrgerant charge for the system.

How do you repair a refrigerant leak?

To fix the leak you will require a licensed HVAC professional.

What to do if you suspect you have a refrigerant leak on your air con

At Sun City Air Conditioning we diagnose and repair leaks on air conditioners all the time - so don't hesitate to contact us if you suspect you have a leak.

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