Learning Center » A/C & Heating » What To Do When Your HVAC Compressor Won’t Turn OnWhat To Do When Your HVAC Compressor Won’t Turn On I'm new to hvac. My ac was working fine but it decided to die one day. I've been able to fix my ac, but it continues to happen(the same problem), and it is not easy to get to the ac (it's on the roof). The problem is: there is a switch that provides electric to the compressor and the fan, and it often turns itself off. if the ac stopped working(the fan and the compressor not running), i had to climbed up to the roof just to push that button to make it work again. I would like to know how to prevent it from switching off. Here are some more pictures 1.how to take this cap off- I worry I would break it. 2.this is how it looks when it worked. is it normal for the compressor? I am not a HVAC tech but I do believe that is a high pressure switch that is tripping and there could be a couple of things going on with your unit.

It is tripping to protect the compressor and fan from faulting. I would suggest calling a HVAC company to come take a look. That could be either a high, or low pressure switch. Without more information on the unit, its hard to say for sure which. A high pressure switch usually opens if the coils are dirty or fan is dead. Basically not enough air flowing through the system, so not enough heat is removed. Low pressure switches will open if the refrigerant level is low. Check the documentation for the unit, and determine which switch this is. Or contact a local HVAC company to come take a look. Without more information, and/or more photos, it's not clear what the problem is. Although I commented above that it would be good to hire a qualified person, there are a few things a skilled DIY'er could do in this case. Make sure the main disconnect is off before doing anything. The most common causes for high head pressure are (a) dirty evaporator coils and (b) a poorly functioning condenser fan.

From the photo it looks like that condenser fan motor has many years of use and the run cap for that motor is also old and not protected from weather. If you have a capacitance meter you can check if the run cap is weak. If it is less than 90% of the labeled value, then it must be replaced. Whether or not it is replaced, the capacitor (and any other bare connectors) must be protected from weather in a NEMA 3 enclosure or similar. air filters for hvac systemAnother likely possibility for causing high head pressure is that the condenser motor bearings are worn out and they seize after being run for awhile, tripping the High Pressure Cut Out. cool cube ac unitInspect the motor bearings. ac parts dallas txIf they are somewhat stiff to turn by hand or if they have much play, then your motor is shot.

In that case you need a new condenser fan motor and a new run cap sized for the new motor at the very least. The problem with following this path is that with an old system these repairs might not resolve all your issues and you need a set of gauges and some experience (i.e. a qualified technician) to make a more thorough evaluation about exactly what is wrong and how much money is worth spending on repair. Odds are good that in the right hands this could be economically repaired.Browse other questions tagged hvac compressor or ask your own question.My Window AC Unit Has Stopped Working How Do I Fix This? Question: Recently I unplugged my window mounted air conditioning (A/C) unit as it was running to relocate it. I was not able to relocate it at that time so I plugged it back in and now it will not turn on. It will not blow cold air at all, in fact it won’t do anything, it will NOT turn back on. What may have happened? Did I break something by unplugging it while it was running?

Please help as it is getting really hot in here!!!Answer: The most probable cause of your AC unit not turning back on is the compressor needs to cool down. (See picture below to see what the compressor looks like and where it is located.) Since you unplugged the unit as it was running, it will not start back up right away as it needs a “cool down period”. There may also be a time delay built into your ac unit to protect itself. It is also possible that by unplugging it while it was working, that you may have tripped a breaker. Go to the fuse/circuit box and check to be sure that nothing has tripped. If a circuit has tripped, go ahead and reset it to turn power back on. If the circuit was tripped and you flipped it back on and the AC still will not turn back on, then give it time to either cool down or let the time delay play out. Check to be sure that your ac unit is not plugged into a GFCI outlet or possibly there is a GFCI reset on the power plug itself. Make sure nothing has reset.

If the AC still won’t turn back on, simply have patience and give it the time it needs to start back up. If the above fixes do not work, there may be more to it then a time delay or tripped breaker. Have a look at the AC parts diagram below. If your window AC is now working properly, here is the best way to clean it out to maintain maximum efficiency.Have any other tips to fix a window mounted AC? Please leave a comment below.Please Share Our Helpful DIY Information Previous post: Water Heater Making Noise? Here Is What To Check Yourself!Next post: What To Do If A Room Is Hotter Than The Rest Of Your House In The Summer LG Air Conditioners Support Need product information or service information? Please enter search keywords here Select a product category or enter keywords to find the information you are looking for. Appliance Accessories & Parts Maintain the efficiency and performance of your LG home appliance by replacing refrigerator and dryer filters on a regular basis.