SAN DIEGO, CALIFORNIA — Chances are you won’t think too much about your heating and cooling system until you notice something wrong with it. One of the problems that we get calls about is the unit turning on, running for a short period of time and turning off again — over and over again. “When an air conditioning system is rapidly starting and stopping, it’s called short cycling,” says Gabriel Carini, the founder and owner of our San Diego air conditioning and heating company. “It’s a problem because it shortens the overall life of your HVAC system and can drive up your energy costs.” There are several reasons that can cause a heating and air conditioning system to short cycle, but most of them can be prevented or corrected with a few simple steps. A short cycling unit may be the symptom of a refrigerant leak somewhere within the AC unit. The simplest fix is to add refrigerant and recharge the air conditioning unit; however, that is only a temporary solution.

Instead have an air conditioning repair and service technician find and repair the leak to prevent the refrigerant from leaking out again and causing the system to short cycle. When the evaporator coil or cooling coil of the unit gets covered in ice or frost, it can cause the unit to malfunction by turning on and off in short bursts. one ac unit vs twoThis can typically be fixed by turning off the air conditioning unit and letting the ice melt, then checking the air filters, cleaning or replacing dirty ones.what are the best ac units for homes When a unit is sized correctly, it is capable of removing the heat as quickly as it comes in to the home or business Ideally, the system should be able to keep up with the incoming heat without gaining on it. how to determine size of ac unit

An over-sized unit will be able to cool the space too quickly and cycle on and off. Every time the system starts up again, it requires a lot of electricity, decreasing efficiency and increasing the electric bill. “Another drawback to an over-sized unit is that it may not run long enough to remove water from the air, which can result in humidity problems,” says Carini. Sometimes short cycling is caused by an electrical fitting, control board or control switch that has been damaged, jiggled loose or completely broken. Simply replacing, repairing or reconnecting the fitting will resolve the problem and eliminate the short cycling. “Most of the causes of a short-cycling unit are issues that would have been inspected and fixed during a routine heating and air conditioning service,” says Carini. “Investing in biannual tune-ups and changing your air filter every month will keep your HVAC system from having this type of problem.” Biannual tune-ups can be scheduled separately or purchased as part of the routine maintenance agreement.

During a tune-up, the technician performs a 22 point inspection of the unit, making adjustments and minor repairs where needed. As for over-sized units, they can be replaced with a unit that is the proper size. If it needs any expensive repairs or if it is 10 or more years old, homeowners may be better off replacing the unit with a two-stage unit. “A properly-sized two-stage cooling unit is the ideal option for  homeowners who are replacing their unit anyway,” says Carini, who also specializes in business heating and air conditioning services. “These systems are very efficient and effective, particularly for people in San Diego’s relatively mild climate.” Two-stage cooling means that the air conditioning unit or heat pump has a compressor with a high setting for extra hot weather and a lower setting for milder weather. The maximum output is rarely needed for San Diego residents since temperatures are typically mild, so the system is running at the lower, more efficient setting.

“These systems are more efficient and less expensive to operate than regular systems, but they also provide more consistent temperatures and more effective humidity control,” says Carini. With some basic monthly maintenance tasks and twice a year service appointments, you can avoid most short cycling problems. If you need to replace your system, we would be happy to assess your home or business and discuss the options for your situation. © 2013 Gabriel Carini. Authorization to post is granted, with the stipulation that Gabriel Carini is credited as sole source. Linking to other sites from this press release is strictly prohibited, with the exception of herein imbedded links. My air conditioner unit outside keeps on turning off and the fan in the house keeps on running. When I switch the circuit breaker off, then on the outside unit works again. Do you know what might be going on? Here are some things that you can do: check the air filter, could be frozen or dirty

check for any possible ice build-up shut down the system from the breaker for 30 minutes: this will reset the system and allow time to melt any ice build-up. Power back on and see if the temperature holds and the system stays on. Here is what I would recommend to have a professional do Verify that the thermostat is working correctly, a bad thermostat would give the results you are getting. Have the pressure checked. Too much or too little refrigerant can affect the efficiency of the unit and may cause it to cycle too much and shut down. In my experience, I would tend to lean towards the thermostat since the system works properly after you've powered it off and back on. If the system cannot determine the temperature after a certain period of time (varies by manufacturer) it will shut itself down as a safety feature since it could run indefinitely and cause damage to the system.Short on-off cycling of air conditioner or heat pump compressor/condenser unit diagnosis:

What causes the A/C or heat pump fan condenser unit to keep cycling on and off rapidly and how do we fix it? Here we explain the common causes of compressor unit short cycling. This article series explains how to diagnose an air conditioner or heat pump that is not cooling: this article explains Joe said: short cycling air conditioner compressor diagnosis: I have the same problem as Mathew: my A/C compressor cycles on and of every ~10 seconds. I is about 5yr old. What can we do to fix this system. Matthew said: short cycling air conditioner problems: Our air conditioning compressor cycles on and of every few seconds or minutes. What can we do to fix this systems not even a year old This was an interesting article. My central AC works perfectly during the night, but short cycles 5 seconds on, half second off on hot days. Any thoughts as to what would be causing this? 2016/09/12 Linda Jackson said: Our Trane Ac unit keeps cycling on and off about every 10 seconds.

York 3 ton heat pump. Heatpump kick on and right back off? Super heat is perfect!! I'm lost plz help! Unit is jumped and and cools great great pressures, but kicks off as soon as it kicks in when wired properly? (mod) said to Joe and Matthew, Mike, Linda and others (re questions just above): An air conditioner or heat pump that is cycling off and immediately back on or cycling off/on every 10 seconds is abnormal and is likely to damage the equipment. I would turn the system OFF while waiting for repair, as I worry that more components will be damaged. I suspect this is a control board or relay problem, possibly related to operating temperature or pressure but that's as far as I can get. Short-cycling on and off of an A/C compressor unit every few minutes (say 1-5 minutes) sounds to me like a diagnosis and repair are needed. A second sort of "short cycling" of the compressor also suggests that diagnosis and repair are needed: if an air conditioner or heat pump compressor runs for a very long time (i.e. the cooling system is not able to reach the indoor set point on the thermostat) and the the compressor shuts off for just a few minutes, then re-starts, I suspect trouble.

Causes include lost refrigerant, ice-blocked cooling coils, thermostat not working properly (blocked, in sun, in airflow, dust-crud clogged). But if someone is turning the system on and off quickly, the compressor may have a hard time re-starting against the pressure on its outlet side. A starter capacitor addition or replacement might fix the problem. If your A/C compressor is showing this symptom but works OK if you leave it shut off for 30 minutes or longer, that may be the trouble. We have also see or a damaged compressor internal refrigerant valve causing high head pressures; In sum, you need a service call from a professional to correctly diagnose and repair the problem. Ask the service tech what she/he found and let us know - what you find will help other readers. Overall: I'd like to see a compressor/condenser unit ON cycle time of 10-20 minutes. The length of time before the next ON cycle of the compressor/condenser unit isn't standard but it ought to be more than 5 minutes, perhaps 10 or more.

The rate of heat gain, air leakage and other factors determine how quickly a cooled space heats-up again once the cool air flow stops. If an A/C or heat pump compressor/condenser unit is on about half-time and is cycling on/off say 3 times in an hour in hot weather while cooling a residential building with typical insulation, air leakage rate, and heat gain rates for its climate, that's probably normal. In very hot weather an air conditioner or heat pump system may run continuously or nearly continuously as long as the indoor thermostat is calling for cooling. It's possible for a residential air conditioning system to be operating normally when a compressor shuts off, then turns back on depending on the system's controls. That's so if the "off" period is long - perhaps 10-15 minutes depending on weather conditions and system capacity. In moderate heat, 10 minutes on and 10 minutes off would not be abnormal but in my OPINION it's close to the edge. A compressor motor that is cycling on and off rapidly is going to be damaged by that condition and depending on the system design, it may also ultimately have trouble re-starting against high head pressure in the system.