Off-Peak Hot Water Start Times Explained (NSW, VIC, QLD)

Short answer: off peak hot water is typically switched on overnight, most commonly sometime between about 10 pm and 1 am and kept available until early morning. In NSW this is called Controlled Load 1 (overnight only) or Controlled Load 2 (longer windows). In QLD it’s Tariff 31 (nights) and Tariff 33 (long hours, any time). In VIC, your distributor runs an overnight window that varies by area. The exact start time at your house is set by the electricity distributor’s control signal or your meter’s contact, not by you, and it can differ from your neighbour’s.

Who actually sets your off-peak start time

Off-peak hot water is powered from a dedicated “controlled load” circuit. The power to that circuit is turned on and off by:

• A distributor control signal (ripple control) sent over the network, or
• A contact in your smart meter that follows the distributor’s schedule, or
• In older VIC setups, a time clock installed by the distributor.

Your electricity retailer bills you for the energy, but the schedule is set by the distributor for your area:

• NSW: Ausgrid, Endeavour Energy, Essential Energy
• VIC: AusNet, CitiPower, Powercor, Jemena, United Energy
• QLD: Energex (SEQ), Ergon Energy (regional)

Key point: You can’t pick the exact start time yourself. Distributors stagger start times street-by-street to spread demand, and they may update schedules from time to time.

Daylight saving can make this confusing. Some distributor signals follow standard time year-round, so your hot water may appear to start an hour later by the clock in summer. Smart meters often handle daylight saving automatically, but not always.

Typical start windows by state

NSW (Controlled Load 1 and 2)

Most homes with off-peak storage are on Controlled Load 1 (CL1), which is an overnight window — generally late evening through early morning. Controlled Load 2 (CL2) offers longer daily availability (often several blocks across the day and night) and is useful if you need daytime reheats. The exact hours are set by Ausgrid, Endeavour or Essential and vary by zone; start times are staggered so your tank may energise at, say, 10:30 pm while another street starts at 11:15 pm.

VIC (Distributor off-peak windows)

Victorian distributors run dedicated off-peak windows for hot water that are typically overnight. Older installations may use a mechanical time switch (which can drift), while newer smart meters switch a dedicated contact on a set schedule. Expect an overnight start sometime around late evening to after midnight, depending on your distributor and area. Some areas provide a short afternoon or early-evening boost as well, but don’t assume this without checking.

QLD (Tariff 31 and 33)

In Queensland, Tariff 31 (often called “Super Economy”) supplies at least eight hours per day, generally overnight. Tariff 33 (“Economy”) supplies at least eighteen hours per day and can switch off during network peaks — meaning your hot water can run in multiple blocks spread across the day and night. Energex and Ergon manage these schedules and may adjust them seasonally or for load management. Start times are not customer-selectable.

How to find your actual start time

1. Check your bill for the tariff name. Look for “Controlled Load 1/2” (NSW), “Dedicated Off-Peak/Controlled Load” (VIC), or “Tariff 31/33” (QLD). Knowing which you’re on narrows the likely window.
2. Look at your switchboard. There’s usually a separate breaker labelled “Hot Water” or “Controlled Load.” If it’s on a timer (older VIC), note the dial time — but remember, distributors may still override it via the meter in newer setups.
3. Watch your meter/app. Many smart meters show which register is active (e.g., CL1). If you have an in-home display or a retailer app with interval data, note when usage spikes overnight — that’s likely the element switching on.
4. Do a one-night test. Late evening, run a hot shower to draw down the tank, then stop. Check when the cylinder warms (hand on the side near the element, carefully) or when the meter shows higher draw. That’s close to your start time.
5. Call your retailer or distributor. Ask for the controlled load schedule for your NMI and whether daylight saving affects it. Distributors can tell you the applicable control group for your address.

If you suspect your hours shifted, remember daylight saving and network updates can change apparent times by the clock. Older time clocks can drift minutes per month — a licensed electrician can re-set or replace them.

Can you change it? Practical options

You usually can’t set a new start time, but you can change how your system uses off-peak power:

• Go from overnight-only to longer windows. In NSW, moving from CL1 to CL2 can allow daytime top-ups. In QLD, Tariff 33 provides more hours than Tariff 31. Ask your retailer about availability, pricing, and any extra daily supply charge for an additional tariff.
• Add a day boost on general supply. Some storage tanks have a second (top) element you can wire to general supply via a boost switch or timer. A licensed electrician is required, and your ongoing cost depends on your peak or shoulder kWh rates.
• Upsize the tank, not the hours. If you regularly run out before the overnight reheat, a larger cylinder or a higher-power element (e.g., 3.6 kW instead of 2.4 kW) can recover more within the same off-peak window.
• Heat pumps and solar PV: consider daytime heating. Heat pumps are most efficient in warmer air, so night-only control can reduce performance. Many households move heat pumps to general supply with a timer for midday, ideally when rooftop PV is generating. Alternatively, some areas offer a longer controlled load (CL2/T33) that includes daytime blocks.
• Thermostat rules still apply. By law, storage hot water must be set to at least 60°C to control Legionella. A tempering valve mixes it down to about 50°C at the taps. Don’t lower the thermostat to “stretch” hot water — it’s unsafe and non-compliant.

Any wiring or tariff change needs a licensed electrician, and your retailer may need to reconfigure the meter. Ask about fees before you proceed.

Costs and running strategy

Controlled load energy is usually cheaper per kWh than your peak rate, which is why resistive storage heaters are commonly put on off-peak. However, factors to check:

• Daily charges: Some retailers add a separate daily supply charge for a controlled load tariff. If your usage is low (e.g., small household, heat pump), that charge can offset the kWh savings.
• Time-of-use vs controlled load: If you don’t have a dedicated controlled load circuit, a timer on general supply can chase cheap shoulder/overnight rates on a TOU plan — but you’ll compete with other loads and it’s not as “guaranteed” as a distributor-controlled window.
• Solar households: If you have PV, daytime heating (heat pump or a diverter feeding a resistive element) can be cheaper than night off-peak, because you’re using your own generation. See our guide to solar hot water and PV diverters.
• Comfort vs economy: If you often run out at night, paying a little more for longer controlled load access (CL2/T33) can be cheaper than repeatedly boosting on peak power.

Common edge cases and fixes

• Daylight saving shifts the clock. If your off-peak seems one hour “late” in summer, this is normal for some control signals. You can’t change it, but you can adapt by slightly reducing late-evening hot water use.
• Ripple control outages. Occasionally the control receiver or meter contact fails and your tank never heats. If you notice no hot water by morning, check the hot water breaker and call your retailer; they’ll organise a distributor check.
• Old time clocks drift. In parts of VIC, legacy time clocks can wander. An electrician can re-set or swap to a meter contact schedule if the distributor supports it.
• Heat pump underperforming at night. Move to a longer controlled load with daytime windows, or rewire to general supply and use a midday timer. See our guide to heat pump hot water.

How long will reheating take?

Roughly: a typical 250 L electric storage tank needs around 6–8 kWh for a substantial top-up, which a 3.6 kW element can deliver in a couple of hours; a full cold-to-hot heat can take 3–6 hours depending on size (e.g., 315 L) and inlet temperature. If your household often empties the tank late at night, make sure your element size and off-peak window can cover the required energy by morning.

Bottom line: off peak hot water start times are set by your distributor and usually kick in overnight. Work out your exact schedule, then tune your system — tariff, tank size, element power, or timer strategy — so you have enough hot water at the lowest sensible running cost.