Every winter, gas pressure drops in many Pakistani cities just when you need heat the most, and LPG prices keep climbing. If you have a heat and cool inverter AC, it can warm your room safely and, in many homes, more cheaply than a gas cylinder heater. In my 10 years of fixing ACs in Islamabad and Rawalpindi, I have found that most families never use this feature, or use it with settings that waste electricity. This guide shows you how to use your AC heater in winter the right way.
Quick answer: press Mode on the remote until the sun symbol or “Heat” appears, set 22 to 24°C, keep the fan on Auto and point the louvers down. A 1.5 ton inverter AC usually uses about 0.8 to 1.2 units of electricity per hour in heat mode.
Does Your AC Have Heat Mode?
Not every AC can heat. Check these three things:
- Remote: press Mode several times. If a sun symbol or the word “Heat” appears, your AC can heat. If you only see Cool, Dry, Fan and Auto, it is a cooling-only model.
- Model name or box: look for “Heat & Cool”, “H&C” or “Heat and Cool” on the box, the indoor unit sticker or the warranty card.
- Type: most heat and cool ACs in Pakistan today are inverter models. Old non-inverter ACs are usually cooling only.
A cooling-only AC cannot be converted into a heater, and pressing Heat on a universal remote will not make it heat.
How to Turn On AC Heater Mode: Step by Step
- Clean the filters first. Dusty filters left over from summer block air and make heating slow. Rinse them with water and let them dry.
- Switch on the AC and press Mode until the sun symbol shows.
- Set the temperature to 22 to 24°C. Setting 30°C does not heat the room faster. It only makes the compressor run harder and raises the bill.
- Keep the fan on Auto.
- Point the louvers downwards. Warm air rises, so blowing it low heats the room evenly.
- Wait 2 to 3 minutes. In heat mode the indoor fan waits until the coil is warm, so it does not blow cold air at the start. This is normal.
- Close doors and windows and draw the curtains in the evening.
Best AC Heat Mode Settings for Pakistani Winters
| Situation | Temperature | Fan | Tip |
|---|---|---|---|
| Normal evening use | 22 to 23°C | Auto | Doors and windows closed |
| Very cold night (below 5°C outside) | 24°C | Auto | Run 20 minutes before sleeping |
| Sleeping | 21 to 22°C | Low or Auto | Use Sleep mode and the Timer |
| Morning warm-up | 23 to 24°C | Auto | Set the Timer to switch on before you wake |
The button layout is almost the same on every brand. For brand-specific remote help, see our Dawlance AC remote guide and Orient AC remote guide.
How Much Electricity Does AC Heat Mode Use?
An inverter AC does not create heat by burning anything. It moves heat from the outside air into your room, so it gives roughly 3 units of heat for every 1 unit of electricity it uses. That is why it is much cheaper to run than an electric rod or oil heater.
- 1 ton inverter: about 0.6 to 0.9 units per hour
- 1.5 ton inverter: about 0.8 to 1.2 units per hour
- 2 ton inverter: about 1.2 to 1.6 units per hour
Use is higher in the first 20 minutes and on very cold nights, and lower once the room is warm.
Example: a 1.5 ton inverter AC running 6 hours a day for a month uses about 150 to 200 units. In 2026, a non-protected home pays roughly Rs 40 to 55 per unit including taxes, depending on the slab. That adds around Rs 6,000 to 10,000 to the monthly bill. Keep in mind that these extra units can push your whole bill into a higher slab, so check your usual winter units first. Our guide on why the electricity bill suddenly goes up explains how slabs work.
AC Heater vs Gas Heater vs Electric Heater: Cost and Safety
| Heater | Approx. cost per hour (2026) | Safety | Best for |
|---|---|---|---|
| Inverter AC (1.5 ton, heat mode) | Rs 40 to 65 | No flame, no fumes | Bedrooms, homes with weak gas pressure |
| Gas heater on Sui gas | Rs 15 to 40, depending on your gas slab | Carbon monoxide risk in closed rooms | Lounges with good ventilation and steady gas |
| Gas heater on LPG cylinder | Rs 55 to 85 | Carbon monoxide risk, cylinder leaks | Areas with no Sui gas |
| Electric oil or rod heater (2,000 watt) | Rs 80 to 110 | No fumes, but hot surfaces | Short use in a small room |
These figures are approximate. They assume about Rs 45 to 55 per electricity unit, an OGRA LPG price of about Rs 279 per kg (October 2026) and a medium heater burning about 0.2 to 0.3 kg of LPG per hour. Your real cost depends on your slab, the room size and how cold it is outside.
My honest advice: if you have steady Sui gas at a low slab, a properly vented gas heater is still the cheapest. If your gas pressure drops, you use LPG, or you need heat in a bedroom at night, the inverter AC is the safer and often cheaper choice.
Is It Safe to Sleep With AC Heater On?
Yes. Unlike a gas heater or angeethi, an AC heater burns nothing, so it cannot fill the room with carbon monoxide. That makes it the safest heater for bedrooms and for homes with children or elderly people. Two small precautions:
- Dry air: heat mode dries the air. Keep a bowl of water in the room or use a small humidifier if your throat or skin feels dry.
- Do not overheat: 21 to 22°C with Sleep mode is enough for sleeping. Use the Timer to switch it off after 2 to 3 hours.
If you still use a gas heater in other rooms, never sleep with it on in a closed room, and keep a window or ventilator open whenever it runs.
Things That Are Normal in Heat Mode
- Cold air for the first 2 to 3 minutes, or the fan does not start at once: the AC is warming the coil first.
- The AC stops heating for 5 to 10 minutes every hour or so: this is the automatic defrost cycle that clears ice from the outdoor unit.
- Steam or water from the outdoor unit: melted ice from defrosting. Make sure it drains away and does not freeze on a walkway.
- Slower heating on very cold nights: when it is near or below 0°C outside, as in Murree or Quetta, every AC gives less heat. Heating does not stop, it just takes longer.
AC Not Heating in Winter? Common Causes
| Problem | Likely cause | What to do |
|---|---|---|
| Only cold air even after 10 minutes | Mode not set to Heat, or a cooling-only model | Check the sun symbol and the model name |
| Weak, lukewarm air | Dirty filters or dirty outdoor coil | Clean the filters and get the AC serviced |
| Heats a little, then gives up | Low gas due to a leak | Get the leak found and fixed before refilling. See our AC gas charging price guide |
| Cools in summer but never heats | Faulty 4-way (reversing) valve or its coil | A technician job, usually a part replacement |
| Outdoor unit covered in ice for hours | Defrost sensor or PCB fault | Switch off and call a technician |
| AC trips the breaker | Wiring, capacitor or compressor issue | See our AC tripping guide |
7 Tips to Keep the AC Heater Bill Low
- Set 22 to 24°C, never 30°C.
- Close doors and windows, and use thick curtains at night.
- Heat only the room you are in, not the whole house.
- Clean the filters every 2 to 3 weeks in winter.
- Use the Timer and Sleep mode at night.
- Keep the outdoor unit clear of leaves, plastic covers and snow, so air can flow.
- Do not switch the AC on and off again and again. An inverter saves the most when it runs steadily at a moderate setting.
Before-Winter AC Checklist
- Wash the indoor filters and check that the drain pipe is clear.
- Remove any cover from the outdoor unit before running heat mode.
- Test heat mode once in November, before the cold arrives, so any fault is fixed in time.
- If the AC was weak in summer too, get a proper service with a gas pressure check. Our AC service price guide lists what it should include.
Frequently Asked Questions
Which temperature is best for AC heat mode?
22 to 24°C for normal use, and 21 to 22°C with Sleep mode at night.
Is AC heater cheaper than a gas heater?
It is usually cheaper than a heater on an LPG cylinder and much cheaper than an electric rod heater. A gas heater on steady, low-slab Sui gas is still cheaper, but it is less safe in closed rooms.
How many units does a 1.5 ton inverter AC use in heat mode?
About 0.8 to 1.2 units per hour, so roughly 150 to 200 units a month at 6 hours a day.
Why does my AC blow cold air in heat mode?
For the first 2 to 3 minutes and during defrost this is normal. If it continues after 10 minutes, check the mode, clean the filters and get the gas and 4-way valve checked.
Can a non-inverter AC heat?
Only if it is a heat and cool model. Most old non-inverter ACs in Pakistan are cooling only.
Sardi mein AC ka heater kaise chalayein?
Remote par Mode dabayein jab tak suraj ka nishan na aa jaye, temperature 22 se 24 rakhein, fan Auto par aur louvers neeche ki taraf kar dein. Darwaze aur khirkiyan band rakhein.
Prices in this guide are approximate for November 2026 and change every month. Gas and electrical faults should always be checked by a qualified technician.
Also read: inverter AC vs simple AC bill difference and how much electricity a 1.5 ton AC uses.