When your air conditioning runs but fails to cool your home effectively, it’s a sign you should call a professional technician to come investigate it immediately. Faulty AC units can lead to costly repairs or even potentially harmful refrigerant leaks which could endanger lives and the environment.
First, make sure your circuit breaker has not tripped; usually this can be reset by switching it off and back on again.
1. Thermostat issues
Your thermostat plays an integral part in communicating with your furnace, air conditioner and heat pump systems in your home. If it stops working correctly, this could result in continuous run time or no cooling whatsoever – though some issues with thermostats are easily resolvable by themselves.
The first step to take when your AC doesn’t produce cool air is to make sure the thermostat setting is correct and that the unit is set on “cool.” If that is indeed the case but no cool air is coming through your vents, calling an HVAC specialist might be necessary.
If your thermostat simply is not getting any power, inspect its unit for signs of wear or a blown fuse or a tripped circuit breaker. Loose wiring could also be to blame but should usually be left up to professionals.
2. Dirty or clogged air filter
Filters that become clogged with dirt, dust and pet dander often prevent air from passing over the blower and cooling coils limiting how efficiently an AC unit cools the space it serves. This significantly diminishes its cooling ability.
Filters that are filthy will recirculate contaminants into your home’s ductwork and throughout your house, potentially spreading mold, mildew and bacteria that pose health hazards. Furthermore, an overburdened blower fan forces it to work harder resulting in an overtaxed motor that could result in costly repair costs or system failure.
If you suspect your AC filter may be dirty, switch it off and remove its cover to inspect it. If it is clean, leave it; otherwise contact a professional for inspection and replacement services.
3. Refrigerant leaks
An air conditioner that leaks refrigerant can be annoying and potentially serious. Refrigerant is essential to the functioning of an AC system as it absorbs heat from inside your home and releases it outside.
Low refrigerant levels can impede this process from taking place effectively, which may explain why warm air might be blowing from its vents even though your thermostat or filter is working perfectly fine.
Refrigeration leaks often result from worn rubber seals on service valve stems becoming worn over time or from condenser coil rust. A professional can generally resolve this problem by fixing leaks and replacing any worn parts.
Signs of refrigerant leakage include hissing sounds emanating from your vents and/or water or refrigerant pooling around the unit. Refrigerant is potentially hazardous and must be handled by professionals with appropriate tools and training for its safe handling, any such signs must be immediately reported immediately.
4. Oversized or undersized unit
If your air conditioning unit is always running but failing to cool effectively, this could be a telltale sign that its size exceeds your needs. If condensation, mold growth or mildew smell are evident then professional assessment could be needed in order to ascertain what size unit would best serve your home.
An air conditioner that’s too large for its home will short cycle frequently, rapidly switching on and off for short bursts that wear down your system while not effectively cooling your space. This short cycling also increases wear and tear on its components while not effectively cooling your living area.
Before purchasing an air conditioning unit for your home, a tech should complete a Manual J calculation to make sure it fits appropriately. Unfortunately, many HVAC techs skip this step and install an air conditioner that’s either too large or small, leading to uncomfortable indoor climate conditions and higher energy bills.
An HVAC technician can perform such calculations for a reasonable fee to ensure your AC fits perfectly with the size and layout of your residence.