Low Or Leaking Refrigerant If you don't have enough refrigerant, the air that's circulating throughout your car's air conditioner can't cool down, and if it gets low enough, your air conditioning system will begin blowing warm air.
Hot air when driving and cold when idling probably means you have a vacuum leak somewhere and the vents are going to “defrost” instead of “people” (it's probably still cold, just not aimed at you). If it was reversed (cold when driving, hot when idling), you need to check your fans and your refrigerant.
Common Causes of an Air Conditioner Blowing Warm or Hot Air
These can be due to clogging issues, electrical problems, low refrigerant, evaporator coil malfunctions, or compressor problems.
This is often due to a clog in the system, a failed compressor or compressor clutch, a faulty condenser fan, a clog in the system, or the actuator directing airflow has failed. It's also possible that the evaporator has frozen over.
Car A/C Only Works When Driving: Causes, Repair Costs, and Upkeep Tips. If your vehicle's A/C only works when your car is moving, you might be dealing with a bad A/C condenser fan, a clogged condenser, or low refrigerant levels.
One of the most obvious signs that your vehicle needs a Freon recharge is that your vehicle will be blowing warm air, even after your vehicle has been running for some time. If your refrigerant gets too low, there will simply not be enough “coolant” to cool the air as it is passed through your evaporator coil.
FAULTY CONDENSER FANS
Defected condenser fans can be among the major causes when air conditioning only works when driving. Condenser fans help reduce the refrigerant's temperature to ensure it condenses. Malfunctions in condenser fans can prevent this from happening.
If your AC is running but not cooling, it could be due to a dirty air filter, incorrect thermostat settings, a malfunctioning thermostat, a refrigerant leak, dirty condenser coils, blocked vents or ducts, a faulty compressor, frozen evaporator coils, or electrical issues.
If your A/C flip-flops from hot to cold and back again, your expansion valve could be failing. The expansion valve removes pressure from liquid refrigerant to allow expansion from a liquid to a vapor state in the evaporator. If the valve is blocked, the refrigerant flow could be restricted or could be too unrestricted.
On average, AC compressor costs range from $800 to $2,300, with most folks paying $1,200 for a new one. However, your price will vary depending on factors like the size and brand of your compressor. Before you schedule your replacement, read on to learn about all AC compressor cost factors.
If the refrigerant levels in the AC system are low, the system will not be able to cool properly. Clogged condenser or evaporator coils. If the condenser or evaporator coils are clogged, the system will not be able to cool properly, especially noticeable when the car is idle. Faulty compressor or fan clutch.
AC repair costs can vary widely, depending on the cause of the problem and the type of vehicle. On average, car AC repair costs run between about $430 and $520. However, if you need a new compressor, you can expect to spend $1,300 to $2,500 or more.
Dirty or Damaged HVAC Ductwork
Blowers circulate the cold air from the central air conditioner to different rooms across the house via the ducts. Damaged ductwork means the cold air leaks out. As a result, the farthest rooms may not receive cold air, and hot air may instead come out of the ducts.
The most common causes of broken air conditioning are leaks or compressor issues. If your air is blowing cool but not cold, the problem could be a clogged filter, cooling fan problem, radiator trouble, or it could simply be that you need to recharge your AC.
We offer an air conditioning regas service from £69.95. The vast majority of cars on the road in the UK use one of two types of refrigerant - R134A and R1234YF. If your air conditioning system requires R134A gas the cost to recharge £69.95.
Possibly your electric radiator fan is not working. When you are driving air flows through due to the forward motion of the vehicle. The A/C condenser is mounted in front of the radiator and uses the same air flow.
What's the Cost of Repairing or Replacing a Fan Motor? The average cost of a condenser fan motor is between $300 and $500 (not including installation). If the compressor breaks, you are looking at a much costlier problem which could cost up to $2000. In some cases, your fan motor may be under warranty.
An AC leak will lead to warmer air from your vents over time. In most cases this can be fixed with a proven stop leak additive to seal up any leaks. When it's time for an AC recharge, turn to AutoZone.
While the refrigerant in your vehicle can escape even without a leak, it's often not enough to cause significant issues unless you've failed to top up the refrigerant for years. When the lack of refrigerant becomes significant though, it can cause a number of problems, including an overheating driver in the summer sun.