What Appliances Use the Most Electricity and Increase Bills?

Appliances that cool, heat, or run for long periods usually have the biggest effect on household electricity use.

Air conditioners, electric water heaters, clothes dryers, electric cooking appliances, refrigerators, and freezers are therefore among the first things worth checking when your electricity bill rises.

But the appliance with the highest wattage is not always the biggest contributor.

A kettle may draw a lot of power for a few minutes. An air conditioner can run for eight hours every night. A refrigerator may use less power at any one moment, but it operates around the clock. Over a month, those differences add up.

Start with cooling, heating, and appliances that run all day

If your electricity use has increased, it makes sense to investigate the biggest loads first.

Air conditioners

Air conditioning can have a major effect on electricity use because it combines relatively high power demand with long operating hours.

An air conditioner running for eight hours every night adds up to around:

8 hours × 30 days = 240 operating hours a month

Consumption also depends on room size, cooling capacity, temperature setting, weather, insulation, maintenance, and the unit's efficiency. TNB recommends using air conditioning efficiently, including setting temperatures around 24°C to 26°C.

Water heaters

Heating water requires substantial energy, so electric water heaters can also add noticeably to household consumption.

Instant water heaters draw high power while they are operating. Storage heaters can use electricity both to heat water and to maintain its temperature. Longer showers, more people at home, or leaving a storage heater running for extended periods can all increase monthly electricity use.

Refrigerators and freezers

Refrigerators and freezers matter because they work throughout the day and night.

Their compressors cycle on and off to maintain the selected temperature.

Electricity use can rise when:

• door seals are damaged;
• the appliance is larger than the household needs;
• ventilation is poor;
• the temperature is set unnecessarily cold;
• doors are opened frequently; or
• the unit is not cooling efficiently.

A refrigerator may not look like a high-power appliance, but 24-hour operation makes it important over time.

What about dryers, ovens, washing machines, and cooking appliances?

Appliances that create heat can use substantial electricity while they are running.

Clothes dryers are a good example because they use heat throughout the drying cycle. Electric ovens must preheat and then maintain a high temperature. Induction cookers and electric hobs can also draw substantial power while cooking. Washing machines generally have a more moderate impact, although consumption depends on how often they are used, programme settings, load size, and whether water is heated.

Here's the thing, a kettle can use more power than a fridge, but still cost less to run

This is where household electricity use can become confusing.

A kettle can have a much higher wattage than a refrigerator, but it may run for only two or three minutes. A refrigerator has a lower instantaneous demand, but it cycles on and off 24 hours a day, seven days a week.

That is why your bill is based on kilowatt-hours (kWh) rather than wattage alone.

The basic calculation is:

Electricity use (kWh) = Power (kW) × Time (hours)

For example, a 1,000-watt appliance equals 1 kW.

If it operates for two hours:

1 kW × 2 hours = 2 kWh

If that happens every day for 30 days:

2 kWh × 30 = 60 kWh per month

For appliances such as air conditioners and refrigerators, actual electricity use may vary because compressors cycle on and off and may not draw their full rated power continuously.

Why can the same appliances suddenly produce a higher bill?

Often, the appliances have not changed, but the way they are being used has.

Imagine a month when:

• the weather is hotter;
• the air conditioner runs two hours longer each night;
• children are home during school holidays;
• the refrigerator is opened more frequently;
• there is more cooking and laundry; and
• showers become longer.

No new appliance has been added, but total household electricity use can still rise.

This is why one of the best questions to ask after a bill increase is:

"What has started running more often or for longer?"

Small daily changes can become significant when repeated across an entire month.

Your appliances are not the only thing that can affect the bill

Household behaviour affects how many kWh you use, but some electricity-cost changes come from outside the home.

Electricity generation costs can also be influenced by factors such as:

• global fuel prices;
• foreign exchange movements;
• actual power-generation costs;
• fuel supply conditions; and
• geopolitical or fuel supply disruptions.

Households cannot control those factors. Under the current electricity-pricing framework in Peninsular Malaysia, changes in generation costs can be reflected through mechanisms such as the Automatic Fuel Adjustment (AFA), subject to the applicable rules and exemptions.

For consumers, what you can control is how much electricity you use and how efficiently your appliances are operated.

Does standby power really matter?

Some appliances continue to draw a small amount of electricity while plugged in, even when they are not actively being used.

Televisions, set-top boxes, gaming equipment, computers, and some chargers can consume standby power. But if your bill has jumped noticeably, small standby loads are usually not the first place to look.

What Malaysia's energy-efficiency stars actually tell you

The Suruhanjaya Tenaga Energy Efficiency Label helps consumers compare the efficiency of similar regulated products.

A higher star rating generally means better energy efficiency within the same product category. TNB recommends looking for 4- or 5-star energy-rated appliances where suitable. But the stars should not be used to compare completely different appliances.

A 5-star air conditioner can still consume more electricity than a fan because cooling a room requires much more energy.

The rating tells you about efficiency, not how little electricity the appliance will use regardless of size or operating hours.

If your electricity bill looks high, check these first

Instead of inspecting every plug in the house, start with the appliances most capable of changing monthly consumption.

Check whether:

1. Air conditioners are running longer, at colder settings, or in more rooms.
2. Water heaters are being used for longer or more frequent showers.
3. Dryers and cooking appliances are operating more often.
4. Refrigerators or freezers are struggling to maintain temperature.
5. A new appliance has recently been added.
6. More people are at home, increasing overall usage.

If your account has an activated smart meter and the relevant data is available in myTNB, daily usage patterns can also show when electricity consumption increased.

It cannot identify the exact appliance responsible, but it can help narrow down what was happening in the home at that time.

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FAQ

Can one faulty appliance cause a sudden increase in electricity use?

Yes. A fault that causes an appliance to run continuously or work harder than normal can increase consumption. Refrigerators, freezers, air conditioners, and water-heating systems are worth checking if their behaviour changes suddenly.

Is it cheaper to use a fan instead of an air conditioner?

A fan generally uses much less electricity because it moves air rather than cooling the room with a compressor. However, the two appliances provide different levels of cooling and comfort.

Should I replace an old appliance just because my bill increased?

Not automatically. First check operating hours, condition, maintenance, capacity, and actual consumption. Age alone does not prove that the appliance is causing the increase.

Can a smart meter tell me which appliance uses the most electricity?

No. Smart-meter data can show when electricity consumption rises, but it does not normally identify the individual appliance responsible.

Are 5-star appliances always the cheapest to run?

They are more energy-efficient than comparable lower-rated products, but actual running cost still depends on appliance size and how long it is used.

Why can my bill increase even if my electricity use stays similar?

Apart from consumption, electricity costs can also be affected by changes in generation costs, including fuel prices and foreign exchange movements. These are separate from household appliance efficiency.

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Last updated: 9 October 2026

This article is sponsored by Tenaga Nasional Berhad.