Written Of course, it would be the hottest day of the year that your air conditioner stops working! Getting it serviced can be expensive, and you'll just have to swelter while waiting for a service technician. Check out these steps that can possibly save some money, and help you keep your cool at the same time! Well, there are many reasons behind it but some normals i whould like to share with you.Is the unit simply not working at all, is it not cooling the air much, or is it simply blowing around warm air?It's not working at all: the condenser (for an outdoor unit) or air handler/furnace (indoor unit) are not running.Make sure it's plugged in. This may seem obvious, but there are occasions when this is exactly the problem. Whether kids, dogs, or an accidental tap with the vacuum cleaner, the plug could be partially or completely dislodged.Check the circuit breakers and fuses. Make sure they are in place, turned on, and functioning properly. Circuits, especially with older homes, are easily overloaded if the air conditioner shares a circuit with appliances such as irons, refrigerators, or microwaves.

Check your thermostat (cooling control) and make sure it is set to cool at the current temperature, and working properly. As with plugs, sometimes settings can change by accident.Check your fan blower belt for excessive slack, damage, or breakage. This can cause low air flow which allows ice to form, and thus causes low cooling performance.Repair or replace the blower belt. Allow the ice to melt before restarting the AC unit.Possibilities:Is air coming out of the supply vents, but it’s just not cold?A dirty air filter blocks airflow to the air handler.  However, this is caused by arefrigerant leak, which you’ll need a professional’s help to find and fix.thank you.Written Air conditioning at a basic level uses electricity to power components to create heat transfer.  You want to transfer heat from inside your house to a coil (thus cooling the house), then transfer that heat (via refrigerant) to outside your house via a coil that rejects the heat to the outdoor air.  The need to understand that electricity powers components, and heat transfer creates the effect of cooling can not be understated. 

Without electricity powering your components properly and heat transfer (via coils and fans) you have no work being done.So we start by checking for power at the indoor and out door units, as well as the thermostat.  used central air conditioner units saleIf all 3 have power (the breakers are on, the fans are turning) then we know we have the high voltages and low voltage present everywhere, (breakers can trips, fuses can blow, and transformers can smoke which all lead to a power loss somewhere).  used air conditioner unit for saleNow that power has been established via fans/noise indoors, outdoors and a thermostat that is working, we need to check heat transfer!  where is the filter on ac unitHeat transfer can be interupted in many ways. 

The simplest ways are to imagine what can mess with a fan blowing air across a coil and mess it up?The fan not turning!The filter being stopped up.The coil being SUPER dirty because the filter is missing( or it is an outdoor unit full of grass/mud)!Most of the problems in the HVAC field are simple issues like these or electrical issues.  It will be uncommon to have to use gauges on a high pressure system unless you are changing out a compressor or unit. Learning some basic electricity and trouble shooting can help you out in a myriad of fields, even plumbing!!  (laws governing flow are consistent whether the potential is measured as voltage or pressure, and whether restrictions are measured in ohms or not. Written The first step would be to determine if your blower motor still operates.  This is easily known by putting your hand up to any supply vent (vents that push out air into your home).  If this is the case, then it's a good bet that the levels of Freon (also known as coolant, refrigerant, etc.) in your your air conditioner are not where they should be.

Occasionally, you could have an air conditioner that has too much Freon, which is causing your system to freeze up, but more than likely you do not have enough Freon circulating through your system, which is causing your air conditioner not to produce cold conditioned air to your home.  It is a common misconception that every so often, one must add a little more coolant to your system, not unlike topping of the oil in your car.  But this notion is false.  The coolant in your air conditioner system actually operates in a closed loop, meaning there is never a need to add more coolant... Unless there is a leak.Leaks are caused by holes, sometimes as small as a pinhole located anywhere where the refrigerant circulates.  The size of the hole determines how long it takes for the Freon (which is actually a gas) to slowly leak out of your system.  If the leak is small, it may take years for the system to lose enough Freon to where your air conditioner is noticeably not producing enough cool air in your home.

Large holes will ensure the refrigerant  leaks out much faster.  Sometimes charging up a system, and spending hundreds of dollars to do so, is the wrong approach, as the Freon will only leak out days, sometimes weeks after it has been recharged. It's always important to have a professional HVAC technician determine where the leak is occurring, and how large the leak is, before regarding your system.Written The compressor is not working due to a motor that is either burnt( which would lead to a short circuit ) or there is a leak in the refrigerant system ( more likely).A good gauge is to check if the air coming out of the condensing coil ( outdoor) is warm ( 40-60°C). If it is, you might have a choked evaporator coil and an overhaul ( Jetclean) would solve that issue.A 24hr high pressure N2 leak test will have to be done if there is a leak in the system. The worse case scenario is when the refrigerant pipes are embedded in the walls or hidden by costly built in cabinets. to be behind that...

All the best in your investigation. Written There are many potential reasons.  I assume that the thermostat is adjusted properly and the power to the indoor and outdoor components has been turned on and the circuit breakers (or fuses) are OK.  I also assume that the unit is indeed blowing air, just not cold air.Go outside and see if the condensing unit is running.  If not then you could have major component failure, a control failure or a loss of the refrigerant charge;If the condensing unit is running, (the fan and the compressor) then take a quick look at the refrigerant pipes connected to the unit.  Depending on the temperature in the house and outdoors the larger of the two pipes should show some condensation.  If the suction pipe (the larger one) is dry then you might have a partial loss of refrigerant charge.The thing is that there are many things it could be.  A trained, experienced, equipped  HVAC tech will breeze through the issues pretty quickly and identify the problem.