Signs of undersizing
The unit runs nonstop and the outlet air is properly cold, yet the room never reaches the setpoint on hot days.
Air conditioning · Troubleshooting weak or no cooling
Air conditioner not cooling: what to check and when to call
Is your air conditioner not cooling? Often the cause is simple: the wrong mode, flat remote batteries, clogged filters or an outdoor unit choked with dust and poplar fluff. When those checks do not help, a technician finds the real fault on site, from low refrigerant to a compressor that refuses to start. The price depends on the cause and access to the outdoor unit, and you get it after sending photos. Book by call, text or WhatsApp.
- Safe checks you can do in ten minutes
- Symptom table to narrow down the cause
- On-site diagnosis before any repair
- Messages and booking in English
Start here
Five checks before you book a technician
A surprising share of "broken" units turn out to be set up wrong. These checks need no tools and carry no risk.
When an air conditioner blows air that is not cold, first confirm it is in cooling mode with a set temperature below the room temperature, then replace the remote batteries, wash the filters and look at whether the outdoor fan is turning. If the outdoor unit stays silent or the air is still warm after twenty minutes, the fault needs a technician.
- 1
Look at the mode symbol
The snowflake means cooling. A fan icon only moves air, the sun heats, and the droplet (dry mode) cools only mildly. Guests and cleaners often change the mode by accident.
- 2
Set a realistic temperature
Choose 22 to 24 degrees Celsius and high fan speed. A setting of 16 does not cool faster. Check that a sleep or eco function is not quietly raising the target.
- 3
Change the remote batteries
A faint display or a remote that needs several presses before the unit beeps means weak batteries, and the unit may still be following an old command.
- 4
Wait a few minutes after switching on
Most units protect the compressor with a short start delay, so give it three to five minutes.
- 5
Wash the filters
With the unit switched off, lift the front panel, slide out the mesh filters and rinse them under a lukewarm tap if the manual allows it. Let them dry before refitting. If the coil behind them looks furred or black, see air conditioner cleaning.
Narrow it down
Symptom table for weak or no cooling
Match what you see and hear to the most likely cause. It is a guide, not a diagnosis.
| What happens | Likely cause | Safe for you to check? |
|---|---|---|
| Air moves, but feels like room temperature | Fan or dry mode selected, setpoint too high | Yes - check the remote display |
| Cold at first, weaker by afternoon | Dirty filters, clogged outdoor fins, very hot facade | Filters yes, outdoor fins no |
| Cooling fades a little more every summer | Slow refrigerant leak | No - see AC gas refill |
| Frost or ice on the pipes or indoor coil | Low refrigerant or badly blocked airflow | Switch off and let it thaw |
| Indoor fan runs, outdoor unit completely silent | Power to outdoor unit, capacitor, control fault | Only the breaker |
| Outdoor unit clicks or hums, then stops | Compressor not starting, weak start capacitor | No - call a technician |
| Unit cools but never reaches the setpoint | Unit too small, heat from sun or roof | Yes - compare room size to capacity |
| Error code or blinking lights | The unit has logged a specific fault | Photograph it and send it to us |
A kitchen thermometer helps. Hold it at the air outlet, then in the middle of the room: a healthy unit usually blows air roughly 8 to 12 degrees colder than the room, while a gap of two or three degrees means a real fault.
Outside the window
A blocked or dirty outdoor unit
The outdoor half has to throw the heat from your room into the street. If it cannot breathe, cooling indoors collapses.
The outdoor unit pulls air through thin aluminium fins and pushes it out through a large fan. In Tbilisi those fins collect street dust, traffic soot and grit from building sites. From roughly mid-May into June, poplar fluff drifts through courtyards in Saburtalo, Vake and along the river and sticks to the fins like felt, so a unit that worked perfectly in April can struggle by the first heatwave.
Enclosed balconies and tight niches
Many older flats have balconies that were glazed in years ago, with the outdoor unit left inside the enclosure, where it breathes its own hot exhaust. New-build units squeezed into narrow niches behind decorative louvers suffer the same way. A technician can judge whether relocating the unit makes sense.
- If the unit stands on your own balcony floor, clear boxes, laundry racks and plants away from it.
- Open the windows of a glazed balcony fully while the air conditioner runs.
- Do not spray water into the fins or poke at them, and never lean over a railing to reach a facade unit.
The gas
Low refrigerant: signs and what really fixes it
Refrigerant circulates in a closed loop and is not consumed. If the level is low, it has escaped somewhere.
Low refrigerant rarely shows up overnight. The usual story is a unit that cooled well two summers ago, felt weaker last year and now barely copes. Other clues are frost on the thinner copper pipe at the outdoor unit, an oily stain at a joint, and an indoor coil that ices over and later drips.
Adding gas without fixing the leak only buys a few weeks. The AC gas refill page explains the right sequence. Refrigerant is under high pressure and can cause cold burns, so never loosen the service valves or pipe nuts yourself.
If you see ice on the pipes or the coil, switch cooling off, run fan mode if you can and let it thaw before the technician arrives. Running it frozen strains the compressor.
Silent outside
The fan runs but there is no cold air, or the compressor will not start
Here the problem is electrical or mechanical, and the checks you can do are limited to the breaker and the error code.
When the indoor fan blows but the outdoor unit makes no sound, cooling cannot happen, because the compressor does the work. Possible causes are a tripped breaker, a failed start capacitor, a burnt contactor, lost communication between the two halves or a control board fault. In older Soviet-era blocks, loose connections on aluminium wiring and low evening voltage can also stop a compressor from starting.
Clicking, humming or tripping
A click followed by a low hum and then silence often means the compressor tries to start and fails. A breaker that trips seconds after start-up suggests a short or excessive current draw. Switch the unit off and leave it off, since repeated attempts can turn a small capacitor repair into a damaged compressor.
- Reset a tripped breaker only once. If it trips again, stop there.
- Count the blinking lights or copy the error code.
- Do not open the outdoor cover or touch any cable. Wiring faults in the flat belong to an electrician, see our electrician page (in Georgian).
On an old unit, especially one on R22 gas, the technician will say honestly whether a new compressor or a new unit is the better deal. For a replacement, the installation page covers capacity and position.
Not a fault
A unit too small for the room, or a Tbilisi heatwave
Sometimes nothing is broken. The unit is simply fighting more heat than it was built for.
Landlords often fit one small unit in the living room and expect it to cool the kitchen and hallway too. As a rough rule, a 9,000 BTU unit suits about 20 to 25 square meters and a 12,000 BTU unit about 30 to 35, while top floors under a flat roof and big west-facing windows need more. The capacity is on the indoor unit's rating label.
July and August heatwaves in Tbilisi can push afternoons toward 40 degrees Celsius, and concrete blocks release that heat well into the night. Even a healthy unit may then hold the room at 26 or 27 degrees. Close curtains on the sunny side, keep other doors shut and start the unit before the flat heats up.
Signs of a real fault
The outlet air is barely cooler than the room, or cooling was fine last summer and is poor now.
Next step
When to stop checking and call
Once the safe checks are done, further experiments only waste time and can damage the unit.
- The air is still warm twenty minutes after you fixed the mode, batteries and filters.
- The outdoor unit stays silent, clicks repeatedly or trips the breaker.
- You see ice, oily stains on the pipes or an error code that returns after a restart.
- You notice a burning smell, buzzing from the socket or heat marks on the plug.
- Water starts dripping indoors as well, which our AC leaking water guide covers.
Send us the video, the photos and what you already tried, and we reply with the likely cause and a starting estimate. Urgent visits are confirmed on the call. For servicing and relocation, see the air conditioner repair hub.
Smoke, sparks or a smell of burning plastic: cut power at the breaker only if it is safe to reach, leave the room and call 112.
FAQ
Frequently asked questions
Why does my AC blow air but not cold air?
Most often the unit is in fan or dry mode, the setpoint is above room temperature, or the filters are clogged. If those are fine and the outdoor unit is silent, the compressor is not running, which needs a technician.
Can I just top up the gas myself?
No. Refrigerant is under high pressure and needs gauges, a leak test and the correct charge for your model. Topping up without repairing the leak also means the problem returns. Read our gas refill guide for how it should be done.
How long should I wait after switching the unit on?
Give it three to five minutes for the compressor delay, then about twenty minutes to judge cooling. If the outlet air is only a couple of degrees below room air by then, something is wrong.
Is poplar fluff really a problem for air conditioners?
Yes, in late spring it can mat over the outdoor fins within days. The unit then overheats and cools poorly. A technician can clean the fins safely, including on units mounted high on a facade.
My AC cools the bedroom but not the whole flat. Is it broken?
Probably not. A single wall unit is sized for one room, and cold air does not travel well through corridors.
Who pays for the repair in a rented flat?
That depends on your agreement with the landlord. Photograph the problem, send the photos to the owner and to us, and settle who pays before the technician arrives.
How much does a no-cooling diagnosis cost?
It depends on the fault and on access to the outdoor unit, so there is no single figure. You get an estimate after sending a description and photos, and any parts are usually bought by the customer unless agreed otherwise.
Contact
Tell us how your AC behaves
A short video of the unit running and a photo of the outdoor unit are usually enough to judge the next step.
Send a short description
Say what you already checked, plus the district, the floor and whether the unit belongs to your landlord.
Next step
Get your cooling back
Send a video and a few photos, and we will tell you what the likely fault is.