My RV's Roof Top Air Conditioner Continually Cycles on and Off
Editor's Note: This question is in reference to a 1998 Nomad Fifth Wheel.Inside AC evaporator coil freezing up:
The air conditioner cuts on, really cools, cuts off then immediately cuts back on continuously. The only way to stop it is to turn it completely off. What causes this to happen and can I fix it or do I need a technician to come out.
ANSWER: Hi, there are several conditions that could be causing the problem you are experiencing with the roof top air conditioner in your RV. Listed below are the most common causes.
Bad Thermostat: I am assuming that you have your RV's AC Thermostat set to Automatic. If the thermostat is not properly functioning it could cause the Air Conditioner to cycle on and off.
Failing Control Board: a bad Control Board in the air conditioner unit itself can also cause the symptoms that you are experiencing.
Both of the items mentioned above would have to be checked out by a Certified RV Technician in order to determine what needs to be replaced or repaired.
I am thinking that this one is the most likely candidate especially if this problem is occurring at night or on humid days. When the AC Evaporator Coil Freezes up the AC unit will start to cycle on and off just like what you are experiencing.
Once the coils are frozen the only way to unfreeze them is to either leave the AC unit off or to run the the AC in "Fan Only" mode until the coils unfreeze.
To prevent this from happening again you may have to run your air conditioner at a higher temperature.
Another way you can help to prevent this from happening again is by making
sure that your Air Conditioner has a clean filter and that there is no dirt or debris on the Evaporator Coil as that dirt can also cause the evaporator coil to freeze up. Follow the two steps outlined below.
1. Clean the AC filters. Dirty AC filters can reduce the cooling capacity and efficiency of your Air Conditioner/s. The filters for RV Roof air conditioners are located inside the RV under the air distribution bezel on the AC unit.
Most RV Air Conditioner filters are made of washable materials and should be washed in warm water carefully and thoroughly. Let them air dry before you replace them. If the filter is torn or will not clean up you should replace the RV Air Conditioner Filter
. You should check and clean these filters at least once a month.
2. Once the filter/s is removed on most RV Air Conditioning units you will be able to see the evaporator coils. Get a flashlight and look at those coils to see if there is any type of accumulation of dirt or debris present, if there is use a very soft bristle vacuum attachment to carefully remove the dust and dirt.
Once you have done the cleaning as outlined above try running the AC again and see if this has resolved the problem. If it does not, then you will need to get a Certified RV Technician to take a look at your air conditioner to find the exact cause of the problem.
Hope this helps.
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