An air conditioner is a device that continuously passes the room's air through itself. Dust, pollen, pet hair and kitchen steam in the air stick a little more to the filter and the indoor unit's coil every day. It is not noticed in the first years; later the unit starts to cool slowly, give off odors and draw more electricity.
In this article we explain why maintenance is necessary, how often it should be done and which steps you can do yourself and which the technician should do.
What is air conditioner maintenance?
Air conditioner maintenance is a periodic procedure consisting of cleaning the indoor and outdoor units, measuring refrigerant pressure, clearing the drainage and checking the electrical connections. The aim is to keep the unit running close to its day-one capacity and to catch small problems before they turn into faults.
Maintenance is not a fault repair. It is done on a working unit and often takes less than an hour. A callout when a fault occurs, on the other hand, takes longer and can leave the unit unusable for days.
Why is air conditioner maintenance done?
There are four basic reasons for maintenance: energy consumption, cooling performance, indoor air quality and unit life. All of them come down to the same thing: dirty surfaces and small leaks that go unnoticed.
01A dirty air conditioner uses more electricity
A clogged filter and a dusty coil make it harder for air to pass through the unit. The compressor runs longer to cool the same room. In unmaintained units we see in the field, consumption is noticeably higher than in a clean unit, and depending on how dirty it is, this difference can reach tens of percent. We covered this topic in detail in our article on energy consumption of an unmaintained air conditioner.
02Cooling and heating capacity drops
When the outdoor unit's condenser fins are covered with leaves, dust and dirt, the unit cannot reject heat to the outside. On the hottest summer days the air conditioner ends up 'running but not cooling', and sometimes it trips on high-pressure protection and stops. In winter heating mode, dirt on the outdoor unit increases icing and defrost frequency.
03Odor and hygiene problems appear
The indoor unit's coil is constantly wet during cooling. When dust builds up on this wet, dark surface, it creates a suitable environment for mold and bacteria. The sour or musty smell you notice when you switch on the air conditioner usually comes from here. This is especially important in homes with allergies, asthma or small children.
04Small problems are caught before they grow
A loose terminal, a worn cable, a small refrigerant leak or a partially blocked drain hose is noticed within minutes during maintenance. If not noticed, it can turn into compressor failure, a burnt board or water running down the wall.
How often should air conditioner maintenance be done?
In a home split air conditioner, filters should be cleaned every 2–4 weeks during heavy use and a technician service should be done at least once a year. If you use the air conditioner for both cooling and heating, two services a year, that is one check before each of the summer and winter seasons, is more appropriate.
| Usage | Filter cleaning | Technician service |
|---|---|---|
| Summer only, a few months | Once a month during the season | 1 per year (in spring) |
| Summer and winter, also used for heating | Every 2–4 weeks | 2 per year (before the season) |
| Pets, smoking, next to a main road | Every 2 weeks | 2 per year |
| Near a kitchen or an environment exposed to greasy vapor | Every 2 weeks | 2 per year, coil chemical wash |
These intervals are general recommendations. The manufacturer's values in the unit's user manual and how dusty the environment is should be the basis. In homes near construction sites or dirt roads, the filter fills up much faster.
Is it time to service your air conditioner?
Our team checks the filter, coil, drainage and refrigerant pressure in a single visit and reports the measurement results in writing.
Maintenance steps you can safely do at home
Cleaning the filter and checking the outside of the unit are jobs the user can and should do. Before starting, switch off the air conditioner with the remote and, if possible, cut its power at the fuse.
- Remove the filters: Lift the front panel and pull the filters out of their slots as shown in the manual.
- Wash them: Clean with lukewarm water, and if needed a little liquid soap, using a soft brush. A hard brush and hot water can damage the filter.
- Dry in the shade: Do not dry the filter in the sun or with a hair dryer; put it back only when it is completely dry.
- Visually check the outdoor unit: Look for leaves, bags or objects piled in front of it and check that the unit stands steady.
- Watch the drain outlet: If water drips regularly from the hose outside during cooling, the drainage is working.
On an indoor unit whose cover is opened, do not touch the fine-finned coil behind the filter with your fingers or a hard brush. The fins are easily crushed and permanently reduce airflow.
Checks the technician should perform
Refrigerant pressure measurement, electrical connections, coil chemical washing and internal cleaning of the outdoor unit should be done by a qualified technician. These jobs require working on the refrigerant circuit and the electrical panel; if done incorrectly, they can harm both the unit and the person.
- Measuring refrigerant operating pressure with a manifold and checking for leaks
- Chemical washing of the indoor unit coil and the fan wheel (blower)
- Clearing the drain pan and hose and checking the slope
- Cleaning the outdoor unit condenser fins with pressurized water or a suitable chemical
- Measuring terminal tightness, cable condition and compressor current
- Measuring the air outlet temperature and recording the results
In cooling mode, a difference of around 8–12 °C is usually expected between the indoor unit's air inlet and outlet temperatures. If this difference has clearly narrowed, dirt, low refrigerant or a fan problem should be investigated. We collected the first things to check for cooling problems in our article on air conditioner not cooling: 7 checks.
When should maintenance not be postponed?
Do not wait for planned maintenance if water drips from the air conditioner, a bad smell comes out when it is switched on, the outdoor unit is noisier than usual or the room no longer cools as it used to. These signs usually point to a clogged drain, a dirty coil or low refrigerant, and early action keeps the repair need small.
It is also a good habit to clean the filters before running an air conditioner that has been off for a long time for the first time at the start of the season. Dust that built up over winter then does not spread into the room on first start-up.
Air conditioner maintenance with YOİ Mühendislik
Since 2009, YOİ Mühendislik has carried out periodic maintenance of split, cassette and multi air conditioners of all brands. At the end of maintenance, we report the measured pressure, current and air outlet temperature to you in writing, so that the unit's condition can be compared at the next service. For details, see our air conditioner maintenance service page.
Frequently asked questions
How many times a year should an air conditioner be serviced?
For a home air conditioner used only in summer, one technician service a year is usually enough. If it is used for both heating and cooling, two services a year are recommended, before the summer and winter seasons.
How often should the air conditioner filter be cleaned?
It should be cleaned every 2–4 weeks during periods of heavy use. If there are pets, smoking or a dusty environment, cleaning every two weeks is more appropriate.
Can I do air conditioner maintenance myself?
You can clean the filter and check around the outdoor unit yourself. Refrigerant pressure measurement, electrical connections and coil chemical washing should be done by a qualified technician.
How long does air conditioner maintenance take?
Standard maintenance of a single split air conditioner usually takes between 45 minutes and 1.5 hours. For very dirty units, this time can be longer once chemical washing and drying time are included.
What happens to an air conditioner that is not maintained?
Energy consumption rises, cooling capacity drops, and odor and water dripping problems begin. In the long term, the risk of compressor and electronic board failure increases.
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