Short answer: press the MODE button on the remote until the display shows a sun or the word HEAT. Set 21 °C, fan AUTO and point the louvres down. For the first 2–5 minutes the unit may not blow at all: every model does this, the indoor unit waits for its heat exchanger to warm up so it does not blow cold air at you.
Below is the full setup step by step, the right winter temperature with an electricity calculation, the differences between brands and the cases where the remote is not the problem. If you are still choosing a unit for winter, see air conditioners for heating.
Setting an air conditioner to heat in five steps
- Switch on with ON/OFF (often marked with a circle and a line). The remote display should show the mode, temperature and fan speed.
- Press MODE until you see the sun or HEAT. Each press changes the mode. On most models the order is AUTO, COOL (snowflake), DRY (drop), FAN (fan) and HEAT (sun), but some brands differ. If you get lost, just keep pressing, the cycle repeats.
- Set 21 °C with the up and down arrows. This is the temperature the unit will keep in the room, not the temperature of the air coming out of it.
- Set the fan to AUTO with the FAN or FAN SPEED button. The unit then gives more air while the room warms up and slows down once it reaches the set temperature.
- Point the louvres down with the SWING button or the arrow icon. Warm air rises on its own, so in heating mode the airflow should start towards the floor.
That is all you need to do once. The air conditioner remembers the last setting and goes straight to heating the next time you switch it on. The other signs on the display are explained in our article on air conditioner remote symbols.
Why the air conditioner does not blow warm air straight away
This is the most common reason people call us at the start of winter. You switch to HEAT, the light is on, and the indoor unit stays silent. The reason is cold-draft protection: the indoor fan does not start until the heat exchanger has warmed up. This usually takes up to 5 minutes, up to 10 in cold weather. Some models show the warm-up with a blinking light.
The second normal effect is a short pause during operation while steam comes out of the outdoor unit. This is defrosting, not a fault. What a normal cycle looks like and when it is a problem is described in detail in our article on air conditioner defrost.
What temperature to set in winter
The guideline is 20–21 °C for the living room and 18–19 °C for the bedroom at night. Every extra degree costs money. We calculated exactly how much for a typical room in Varna:
- a 25 m² room, heat demand of about 2 500 kWh per season at 21 °C (the same basis as in our article on cheap electric heating);
- average outdoor temperature from November to March of about 5 °C (approximate for Varna);
- an air conditioner with SCOP 4.6 and electricity at 0.15 €/kWh.
| Setpoint | Heat demand | Electricity per season | Bill |
|---|---|---|---|
| 19 °C | 2 182 kWh | 474 kWh | 71 € |
| 20 °C | 2 341 kWh | 509 kWh | 76 € |
| 21 °C | 2 500 kWh | 543 kWh | 82 € |
| 22 °C | 2 659 kWh | 578 kWh | 87 € |
| 23 °C | 2 818 kWh | 613 kWh | 92 € |
| 24 °C | 2 977 kWh | 647 kWh | 97 € |
| 25 °C | 3 136 kWh | 682 kWh | 102 € |
Each degree adds about 5 € per room per season, or about 6 %. The difference between 21 °C and 25 °C is 20 €, a quarter of the bill. If you heat three rooms, the amount triples. To see consumption by unit size, read our article on how much electricity an air conditioner uses.
Do not drop the temperature sharply when you go out for a few hours. An inverter uses the most energy when it warms up a room that has cooled down. For an absence of up to half a day it is cheaper to lower the setting by 2–3 degrees than to switch off. If you leave for days, switch off or use the low-temperature hold mode if your model has one (see the brand table).
Fan and airflow direction in heating mode
Fan speed affects comfort more than the bill. On AUTO the unit warms the room quickly and then switches to a quiet speed. A low fixed speed (one bar) is quieter, but the room warms slowly and the air under the ceiling stays warmer than at the floor.
- Louvres down. In HEAT mode warm air has to reach the floor. Blown horizontally, it stays under the ceiling and the unit stops because its sensor at the top already “sees” 21 °C.
- Swing when needed. In a large or long room switch on SWING to mix the air. In a small room a fixed downward direction is more comfortable.
- Do not aim the airflow at the bed or the sofa. Dry warm air blowing directly on people is unpleasant even at the right temperature.
- Close the doors. The air conditioner heats the room it is installed in. An open door to the hallway means it heats the hallway too, only more slowly and with no result.
Heating mode by brand
The basic principle is the same everywhere: MODE to the sun, degrees with the arrows. The differences are in button names and extra functions. The table sums up the most common variants. A specific remote may differ by series, so check your model’s manual if in doubt.
| Brand | Heating mode | Useful in winter |
|---|---|---|
| Gree | MODE to the HEAT sun | TURBO for fast warm-up; on some models a function that holds 8 °C while you are away; I FEEL measures the temperature at the remote |
| Daikin | MODE to HEAT (sun) | POWERFUL for 20 minutes of boosted operation; COMFORT directs air downwards in heating; ECONO limits consumption |
| Mitsubishi Electric | MODE to HEAT | VANE for louvre direction; on models with the i-see sensor it tracks where people are |
| Mitsubishi Heavy | MODE to HEAT | HI POWER for fast warm-up; ECONO for economy mode |
| Fujitsu | MODE to HEAT | on many models a 10 °C HEAT button to keep an empty home at 10 °C |
| Toshiba | MODE to HEAT | Hi POWER for fast warm-up; ECO for lower consumption |
| AUX, Nippon, TechPoint, Kaisai | MODE to the HEAT sun | TURBO, SLEEP and timer; the set of functions depends on the series |
If the remote has a word but no icon, look for HEAT. If it has an icon but no word, look for the sun. The snowflake is cooling and you do not need it in winter.
Night mode, timer and app
SLEEP (usually a moon) gradually lowers the set temperature by 1–2 degrees during the first hours, and the fan goes to its quietest speed. It suits the bedroom: you are not woken by noise and the bill is slightly lower. The exact logic varies by manufacturer.
The timer (ON or OFF with a clock) switches the unit on or off at a set time. The most useful winter combination is TIMER ON half an hour before you get up or come home. You walk into a warm room without the unit running all day.
Wi-Fi models are controlled from your phone. If your model has an app, you can switch the heating on on your way home and see the room temperature while you are out.
When the setting is not the problem
If you have done the five steps, waited 10 minutes and there is still no warm air, check three things:
- The filters. A clogged filter reduces airflow and heating. It takes five minutes to clean, exactly how is described in our article on seasonal air conditioner preparation.
- The outdoor temperature. Every air conditioner has a lower limit for heating. Of the 394 inverter models in stock in our catalogue, 225 heat down to −15 °C and 60 down to −25 °C or lower. For Varna −15 °C is usually enough. If the air conditioner is your only heating or you live inland, see the models in our ranking of heating air conditioners by SCOP.
- An error code. Lights blinking in a certain pattern or a code on the display mean a fault. Settings will not help here, you need a technician. See air conditioner repair in Varna.
If the unit is old and has not been serviced for more than a year, the most likely cause is a dirty heat exchanger or low refrigerant. Servicing a standard wall-mounted air conditioner in Varna costs 42 € with us, details are on the air conditioner servicing page.
If you need an air conditioner that heats in the cold
If your current unit cannot cope, look at two numbers in the specifications: SCOP (seasonal heating efficiency) and the lower limit in heating mode. Examples from the catalogue with prices as of 14.10.2026:
| Model | BTU | Heats down to | SCOP | Price |
|---|---|---|---|---|
| TechPoint TCP H09 MAXCOOL | 9 000 | −15 °C | 4.0 | 300 € |
| Nippon NPC 09 T-PRO NORDIC | 9 000 | −25 °C | 4.6 | 475 € |
| Gree Charmo GWH09ATCXB | 9 000 | −25 °C | 4.8 | 714 € |
| Nippon NPC 12 T-PRO NORDIC | 12 000 | −25 °C | 4.7 | 525 € |
| Gree Amber GWH09YD | 9 000 | −30 °C | 5.1 | 996 € |
The size is chosen by floor area: a 9 000 BTU unit for 15–25 m², a 12 000 BTU unit for 25–35 m². All models by capacity are on the 9 000 BTU air conditioners and 12 000 BTU air conditioners pages, and the full list is in the inverter air conditioners category.
What to do now
If the unit heats after the five steps, leave it on 21 °C and AUTO. If it does not, clean the filters and try again. If there is still no warm air, call us for a diagnosis. For a new unit with professional installation see air conditioner installation in Varna.
Frequently asked questions
How do I set my air conditioner to heat?
Switch on with ON/OFF and press MODE until the display shows a sun or the word HEAT. Then set 21 °C and fan AUTO.
What is the heating symbol on an air conditioner?
The sun, sometimes with the word HEAT. The snowflake is cooling, the drop is dehumidifying, the fan is fan only.
What temperature should the air conditioner be in winter?
20–21 °C during the day and 18–19 °C in the bedroom at night. For a 25 m² room in Varna each degree above 21 °C adds about 5 € per season.
Why does the air conditioner not blow straight away after I switch it to heat?
The indoor fan waits for the heat exchanger to warm up so it does not blow cold air. This takes up to 5 minutes, up to 10 in cold weather.
Is it better to run the air conditioner all the time in winter?
For a short absence of up to half a day it is cheaper to lower the setting by 2–3 degrees than to switch off. Warming up a cold room uses the most electricity.
How do I set a Gree air conditioner to heat?
Press MODE until the HEAT sun lights up, set the temperature with the arrows and choose the fan speed. Some Gree models also have a function that holds 8 °C when the home is empty.
What should I do if the air conditioner is on HEAT but does not heat?
Clean the filters and wait 10 minutes. If there is no warm air or an error code is showing, call a technician for a diagnosis.
