What It CostsWhat does an electric water heater cost to run?
Electric water heater running cost
$62.10 a month ≈ $744.60 a year
That is 12.00 kWh a day · $2.04 a day · $0.68 an hour while it runs
- Electricity used a year
- 4,380 kWh
- Cost a week
- $14.28
- Cost a year
- $744.60
Enter element run time, not hours the tank is switched on. A household of four typically calls for 2–4 hours of a 4 kW element a day, spread across the day in short bursts.
One thing off the bill each month
MonthlyOne appliance a month worth measuring or changing, and what it does to the yearly total. No tariff pitches, no prices — the numbers that stay true.
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How much does an electric water heater cost to run?
A 4,000 W element running three hours a day costs about $2.04 a day at $0.17 per kWh — $62 a month, £91 at £0.25, or €128 at €0.35. Over a year that is 4,380 kWh, which in an all-electric home is usually second only to heating.
What you are paying for is two things: the hot water you actually use, and standing loss from the tank while it waits. A modern well-insulated cylinder loses a little; an old one in an unheated space loses a lot, and that loss runs 24 hours a day whether anybody showers or not.
Three things move the number. Temperature — 60 °C is the sensible setting and every degree above it is standing loss for nothing (do not go below 60 °C on a stored tank; that is the legionella threshold). Insulation — a cylinder jacket on an old tank pays for itself within months. And a heat pump water heater, which uses roughly a third of the electricity for the same hot water and is the single biggest available change here.
Hot water for a family of four, a year at a time.
| System | kWh a year | At $0.17 | At £0.25 | At €0.35 |
|---|---|---|---|---|
| Old cylinder, poor insulation | 5,000 | $850 | £1,250 | €1,750 |
| Modern insulated cylinder | 4,000 | $680 | £1,000 | €1,400 |
| Cylinder + jacket + 60 °C setting | 3,500 | $595 | £875 | €1,225 |
| Heat pump water heater | 1,400 | $238 | £350 | €490 |
| Solar thermal + electric backup | 1,800 | $306 | £450 | €630 |
The gap between the first and fourth rows is bigger than most households’ entire lighting, entertainment and computing use combined. If one appliance in the house is worth replacing on running cost alone, it is usually this one.
Frequently asked questions
How much electricity does heating water use per year?
In an all-electric home, typically 3,000 to 5,000 kWh a year for a family — $500 to $850 at $0.17, £750 to £1,250 at £0.25, or €1,050 to €1,750 at €0.35. It is usually the second largest line after space heating, and the largest in a mild climate.
What temperature should the tank be set to?
60 °C (140 °F) on a stored-water cylinder. Below that, legionella can develop in the tank — this is the one place on this site where turning it down to save money is the wrong advice. Above 60 °C is pure standing loss and a scalding risk; blend down at the tap instead.
Is a heat pump water heater worth it?
It uses roughly a third of the electricity for the same hot water, because it moves heat from the air rather than making it. On a 4,000 kWh a year household that is a saving of about 2,600 kWh — $440, £650 or €910 a year. Payback is usually a few years, faster where electricity is expensive.
Does a timer save money?
Some, and more on a time-of-use tariff. Heating the tank on a cheap overnight rate and letting it coast through the day is a real saving; heating it four times a day on demand is not. On a flat tariff the saving is only the reduced standing loss from not reheating a tank nobody will use.
Is an instant or tankless heater cheaper?
It removes standing loss entirely, which is the main advantage, and it never runs out. Against that, it needs a very large electrical supply — 20 to 30 kW for a whole house is common — which many homes cannot provide without an upgrade. Energy used for actual hot water is much the same.
How do I know my element's run time?
A smart meter with half-hourly data shows it clearly as regular blocks. Failing that, the tank’s own thermostat light, or an estimate: roughly 0.06 kWh per litre of water heated from cold to 60 °C, so a 10-minute shower using 80 litres is about 4.8 kWh — a bit over an hour of a 4 kW element.
How we calculate this
Worked example
With Appliance Electric water heater, Power it draws (watts) 4000, Hours a day 3, Days a week 7, Country United States (USD), Your price per kWh 0.17, this page works out $62.10 a month ≈ $744.60 a year. That is 12.00 kWh a day · $2.04 a day · $0.68 an hour while it runs
- Electricity used a year4,380 kWh
- Cost a week$14.28
- Cost a year$744.60
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