9 Signs of Low Refrigerant Fluid

A low refrigerant fluid makes your AC lose efficiency. The bigger sign that your vehicle is low on refrigerant fluid is the AC not cooling or blowing cold air. This is because refrigerant fluid is a key element in the air conditioner's role in converting hot air into cold air.

The refrigerant fluid is vital for the AC system. Therefore, if your vehicle is low on refrigerant it'll show different signs, especially concerning the cooling efficiency. In addition, an air conditioner with low refrigerant fluid can develop damage, causing even further symptoms.

• Key function: The main role of the refrigerant fluid is to absorb the heat from inside the vehicle's cabin. After the absorption, the vehicle's interior cools due to the removal of hot air, becoming more comfortable.

A vehicle AC with low refrigerant fluid can result in progressive damages after a while.

• Safety: The refrigerant fluid is vital for comfort as it ensures the air conditioner avoids too much heat inside the cabin. In addition, air conditioning components like the AC compressor, suction line, refrigerant lines, and AC vents can overheat and burn without refrigerant fluid, releasing burning smells and toxic fumes. 

Burning rubber/Burning plastic smell

Many AC components can overheat and burn away. Since these components are typically made of plastic and can involve wiring and rubbery insulation, they might release a burning rubber or burning plastic smell when they overheat.

An air conditioner low on refrigerant fluid won't be able to regulate temperature, which can quickly result in an "overheat" scenario. This means that many components inside the HVAC system are prone to develop damage due to excessive heat. Some components that can quickly burn and release burning smells are the AC compressor, the AC evaporator, etc.

AC is not cooling

When you're low on refrigerant fluid, your vehicle's AC won't properly switch the hot air inside the cabin with cold air. This is because the refrigerant fluid is the key piece in this process; this fluid absorbs the heat inside your car, lowering the temperature you feel.

Unless you have enough refrigerant, the vehicle won't have a working AC. Additionally, the AC might start overheating and develop electrical failures, which damage other components like the evaporator and compressor. This results in even more repairs and a less reliable air conditioning system.

Other common signs

Here are other common signs that your vehicle’s refrigerant fluid is low:

• Warm Air from Vents
• Intermittent Cooling
• Hissing or Bubbling Sounds
• Visible Refrigerant Leaks
• A/C Clutch Not Engaging
• Ice on the Compressor
• Dashboard Warning Light

Possible fixes

• AC control unit replacement: If your vehicle is dry on refrigerant, the AC control unit may have malfunctioned due to an inability to regulate the system properly, necessitating its replacement.
• HVAC control replacement: A lack of refrigerant can cause the HVAC control system, including the heat pump, to fail in maintaining the desired temperature, potentially requiring a replacement.
• AC compressor replacement: Running the AC system without sufficient refrigerant can cause the AC compressor to overheat and seize, leading to the need for a replacement.
• AC condenser replacement: Low refrigerant levels can cause the AC condenser and indoor coil to overheat and become damaged, making a replacement necessary.
• AC control module replacement: The AC control module may need replacement if it is unable to accurately sense and regulate refrigerant levels, leading to improper AC function.
• AC pressure switch replacement: If the refrigerant is low, the AC pressure switch may fail to detect the correct pressure levels, necessitating its replacement to restore proper system operation.
• AC hose replacement: A vehicle dry on refrigerant could indicate leaks in the AC hoses, which would need to be replaced to ensure the system can hold refrigerant properly.

Frequently Asked Questions

How do I know if my AC fluid is low?

The telltale signs of low AC fluid in your car are weak, lukewarm indoor air coming from the vents even on the highest setting, or cool air that gradually warms up during your drive. You might also hear a clicking sound from the AC clutch engaging intermittently, or see oily residue around the AC system indicating a leak. But remember, these could point to other AC issues as well, so consulting a mechanic for a proper diagnosis is always best. In many cases, there's no easy way to directly check the refrigerant level in your car's AC system.  A mechanic or HVAC technician uses special gauges hooked up to the system to measure pressure, which indicates refrigerant level. It's a more complex process that's best left to a professional.

Can I run my AC with low refrigerant?

Absolutely not. Running your AC with low refrigerant is a recipe for disaster. It will strain your compressor and outdoor condensing unit, leading to expensive repairs or replacement. Worse, low refrigerant can cause the indoor evaporator coil to freeze, damaging the system and potentially reducing its lifespan. Play it safe - if you suspect low refrigerant due to weak cooling, shut off the AC, avoid a compressor overheating, and call a professional for a proper diagnosis and recharge.

Can you lose refrigerant without a leak?

Technically, very minimal refrigerant might escape through worn-out components over a long period, but it wouldn't cause major issues unless you haven't refilled the system for many years. A significant loss of refrigerant in air conditioners almost always indicates a refrigerant leak, which needs professional attention to fix and recharge the system.