Why Is My Air Conditioner Starting and Stopping?

Have you ever been outside in the summer enjoying coffee, tea, or even a cold afternoon beer while listening to different sounds during early mornings or evenings in O’Fallon? Leaves rustling, birds chirping, the sound of traffic, the hustle and bustle of the area… Now ask your trusted O’Fallon HVAC technician, and they have a bit of a different story to tell: “those hot summer mornings, the sound of air conditioner compressors turn on over and over and over again”. 

Sometimes, I feel like I can hear those air conditioning parts struggling to start from a mile away; the technician in me just wants to walk down the street and start wrenching them. Unfortunately, we can only wait for a call from some disgruntled homeowner to request regular maintenance that will mitigate these issues on a clearly failing air conditioner in O’Fallon.

Why your O’Fallon HVAC is failing

You may ask, what causes my air conditioner in O’Fallon to cycle on and off without actually cooling the house? 

Tripping on high pressure

It could be a number of things, but usually, on those hot summer days, it is tripping on what we call high pressure. The pressure inside the outdoor unit is so high the equipment knows it is not supposed to operate or it may harm itself. The air conditioner knows by using pressure switches in series with the  compressor, so if the switch is activated, the compressor will not run. Most of the time, this is solved by an easy fix: cleaning the outdoor condenser coil. 

If the outdoor coil is filled with debris, the unit will not properly move air through the sides of the condenser and will start to generate too much heat, overheating, causing the high-pressure switch to trip and shut the unit down. When this happens, the unit will shut down, equalize and then try to restart once the pressure gets back into the allowable range. The air conditioner will run again until the pressure builds up too high and shuts itself down. 

This cycle will happen over, and over, and over again until the air conditioning equipment has a catastrophic breakdown and will no longer start. Certain air conditioners like a Lennox ML14 have a manual resettable push-button high-pressure switch. When that switch is activated, it will not run the  equipment until the little red button is pushed back in. Unless you are a licensed O’Fallon HVAC professional, we do not recommend pushing the red button switch back in. Doing so may result in even more damage to the unit.  

If you are unsure why your air conditioning system is cycling over and over again, it may be time to contact an O’Fallon HVAC professional at Stay Cool Climate Control. A lot of these issues can be resolved with general maintenance, so we recommend our Comfort Club Plan to all of our customers. The Comfort Club Plan lets homeowners take their hands out of maintenance and have a worry-free heating and  cooling season.

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