A shock bill is either a price change or something at home using more. Here is how to tell which, and where to look first.
When the electricity bill jumps, first compare the kWh (units) used, not the ringgit: if the kWh is flat, the price changed, not your home. TNB moved domestic customers to a new tariff structure from 1 July 2025, with a monthly fuel adjustment, so the ringgit can move on its own. If the kWh really went up, the usual causes, in order, are an aircon that is dirty or low on gas and runs longer, a water heater left on, a water pump cycling because of a leak, and an old fridge with a failing door seal. True electrical leakage is a safety problem first: warm sockets, a burning smell or a tripping RCCB mean call an electrician, not an energy audit.
Almost everyone who is shocked by a bill compares this month’s ringgit with last month’s. That mixes up two different things: using more electricity, and each unit costing more. Your bill shows the consumption in kWh. Put the last six bills side by side and look only at the kWh.
TNB’s own tariff page explains that from 1 July 2025 the old tiered pricing was replaced by a single energy charge broken into clear cost components, and that a fuel cost adjustment is now updated monthly, replacing the old ICPT mechanism. In practice that means the ringgit on your bill can move from month to month even when your usage does not. Our guide to the 2025 tariff and SST changes has the background.
TNB also lets domestic customers with smart meters opt in to a time-of-use tariff, with cheaper off-peak rates. That only helps if your heavy use, such as laundry, water heating or EV charging, can move to off-peak hours.
| Cause | Why it raises use | What to check |
|---|---|---|
| Aircon dirty or low on gas | The compressor runs longer to reach the same temperature | When it was last serviced; whether rooms take longer to cool |
| Aircon used longer | Hot spell, doors open, set too cold | Hours of use; the set temperature |
| Water heater left on | A storage heater keeps reheating its tank all day | Whether it is switched off after use |
| Water pump cycling | The pump starts whenever pressure drops, including from a leak | Does the pump run when nobody uses water? |
| Old fridge or failed door seal | The compressor runs almost non-stop | Does the door seal close tight? Is the back very hot? |
| New appliance or more people at home | Extra load that is easy to forget | What arrived, or who moved in, in the last few months |
| Loose connection or earth leakage | A safety fault that can also waste energy | Warm sockets, tripping, burning smell |
In most Malaysian homes the aircon is the largest part of the bill, so start there. A dirty aircon does not use a little more; it runs longer. Clogged filters and a dusty coil cut heat transfer, so the room takes longer to cool and the compressor keeps going. Low gas does the same: the unit blows air but never reaches the set temperature to cycle off.
A regular service or a chemical wash is the cheapest fix if the units have not been cleaned for a long time. On our aircon servicing guide, a regular service is RM60–RM120 per unit and a chemical wash RM120–RM250. If the unit is no longer cooling properly, see our aircon repair guide.
A storage water heater heats its tank and then keeps reheating it to hold the temperature, whether anyone showers or not. Left on all day for two showers, most of that energy is wasted. If the bill rose after someone moved in, or after a new heater was fitted, check the switch habit first. Our water heater types guide compares instant and storage heaters.
A water pump that switches on when nobody is using water is a classic hidden load. It usually means water is escaping somewhere, a dripping tap, a running cistern or a concealed pipe leak, so the pressure drops and the pump restarts. You pay twice: on the water bill and on the electricity bill. Our guide to a high water bill and hidden leaks shows how to test for it.
If you still cannot see the cause, a simple test at the meter helps separate a hidden load from a fault:
Work on the DB box itself, beyond switching breakers, is a job for an electrician.
People often blame “leakage” for a high bill. Current leaking to earth through damaged insulation, a wet socket or a faulty appliance is dangerous long before it is expensive. Suruhanjaya Tenaga publishes guidance on the residual current device (RCD, RCCB or ELCB), the switch in your DB box that is there to cut the supply when current leaks to earth and protect people from electric shock. Our wiring safety inspection guide explains what a proper check covers.
| Check | How | What it tells you |
|---|---|---|
| kWh trend | Six bills side by side | Price change or real increase |
| Aircon | Service dates; time to cool a room | The most likely big load |
| Water heater | Is it switched off after use? | All-day reheating |
| Water pump | Does it run when all taps are shut? | A hidden water leak |
| Fridge | Door seal, back of the unit, noise | An old compressor running non-stop |
| Meter test | Everything off, watch the meter | A hidden load, or a supply-side issue |
If the audit points to the aircon or the wiring, these are the related jobs, with ranges from ClickBina guides (indicative 2026, Klang Valley):
| Job | Indicative price | Source guide |
|---|---|---|
| Aircon diagnostic visit | RM120 – RM400 | Aircon repair guide |
| Aircon regular service, per unit | RM60 – RM120 | Aircon servicing guide |
| Aircon chemical wash, per unit | RM120 – RM250 | Aircon servicing guide |
| Electrical fault-finding / tripping diagnosis | RM150 – RM400 | Electrician services guide |
WhatsApp us your job details for a quote — we reply within the hour.
💬 WhatsApp for a quoteServicing an aircon that has not been cleaned for a long time is often the quickest way to bring the kWh back down. Electrical work is done for safety first; any saving is a side effect.
Most sudden jumps trace back to the aircon, and that is where ClickBina can start: an aircon diagnostic is RM120–RM400. For wiring, heaters and pumps, WhatsApp us your job details for a quote: the last few bills’ kWh, which appliances you suspect, and anything that trips or feels warm. ClickBina is an experienced KL & Selangor contractor; we reply within the hour, the price we agree is a flat price with no hidden charges, and a site visit is RM150, waived if you go ahead.
How we estimated prices: every RM figure is quoted unchanged from the ClickBina guides named above; they are typical Klang Valley ranges for 2026, not fixed rates.
WhatsApp us your job details for a quote — we reply within the hour.
💬 WhatsApp for a quoteTell us what you need — we reply within the hour.