Controlled load is a separate metered circuit that supplies one large appliance, usually an electric storage hot water system, at a cheaper rate per unit. Your network operator decides when that circuit is switched on, normally overnight, so the appliance heats during off-peak windows. It is wired and metered separately from the rest of your home.
If your bill shows a second usage line you do not recognise, or the hot water has gone cold while everything else works, controlled load is usually the explanation.
How does controlled load actually work?
Controlled load works by giving one appliance its own circuit that the network can switch on and off remotely. It runs from a dedicated breaker in your switchboard to a single hard-wired appliance, measured on its own meter or its own register inside a smart meter.
The network does the switching, not you. Older installations use a load control signal that closes a relay in the meter box when the window opens, and newer smart meters do the same job with a built-in contactor. You give up control of when the appliance runs, and in return its energy is billed below general usage. A tank holds a full day of hot water, so it makes no practical difference that it heated at 2am.
What is the difference between Controlled Load 1 and Controlled Load 2?
Controlled Load 1 gives the cheapest rate but the shortest heating window, and Controlled Load 2 gives more hours at a slightly higher rate. Which suits a property comes down to tank size and household use.
| Controlled Load 1 | Controlled Load 2 | |
|---|---|---|
| When it runs | Overnight only, typically six to nine hours | Overnight plus part of the day, often sixteen to eighteen hours |
| Rate per unit | The lowest rate available | Higher than Controlled Load 1, still below general usage |
| Best suited to | Larger tanks. Heavy daytime use can empty one before the next window | Smaller tanks, or households that run out by evening |
Your distributor sets the switching times and they vary by area, so treat the hours above as a guide and check your own retailer's plan.
Which appliances can go on controlled load?
Controlled load is only for hard-wired, high-use appliances that can run on a delay. The appliance has to tolerate being switched off for long stretches.
- Electric storage hot water: by far the most common. The tank heats overnight and holds the water until you use it.
- Slab and underfloor heating: the slab stores heat the way a tank stores water, so it suits an overnight charge.
- Pool and spa heating: allowed by some retailers, depending on the plan.
What cannot go on it: power points, lighting, ovens, air conditioning, and anything you expect to work on demand. Instantaneous electric hot water is unsuitable too, because it heats at the tap rather than storing it.
Do I need a special meter for controlled load?
Yes. Controlled load has to be measured separately, so it needs its own meter or its own register inside a smart meter.
Older boards often carry two meters plus a separate off-peak relay, which is why they get crowded. A modern Type 4 smart meter records several registers at once and switches the circuit with an internal contactor, so a changeover usually removes hardware rather than adding it. That is part of a standard smart meter installation.
The catch is board condition. If the board is full, damaged, or built on an asbestos meter panel, the meter cannot simply be swapped. A good installer checks that beforehand.
Why is my hot water cold when nothing else has failed?
If the rest of the house has power and only the hot water is out, the fault is nearly always on the controlled load side rather than your main supply. Four faults cause nearly all of it.
- The controlled load breaker has tripped. Check the board for a breaker labelled hot water, HWS, or off peak. One that trips again after being reset means there is a real fault to find.
- The element or thermostat has failed. A failed element is the most common hot water fault and has nothing to do with the metering.
- The relay or contactor has failed. If the switching device never closes, the circuit never goes live and the tank never heats, even though the breaker looks normal.
- The circuit was not set up correctly after a meter change. The controlled load has to be reconnected and the new meter configured to switch it. Miss that and the hot water works until the tank empties, then stays cold.
Check the board for a tripped breaker and feel whether the tank is warm, but leave the meter box alone. That is live equipment only an accredited Level 2 ASP may work on.
Hot water cold and no idea why?
DM Electrical is Level 1 and Level 2 ASP accredited and based in Brookvale, so the switchboard, the controlled load circuit and the metering can all be sorted by one team. Available 24/7 across the Northern Beaches and wider Sydney.
Should I keep hot water on controlled load if I have solar?
If you have solar and export most of what you generate, heating the tank during the day on your own power can beat the controlled load rate. Every unit that goes into the tank at midday is one you are not selling back at a feed-in rate. It is not automatic, though. It depends on your feed-in tariff, system size, and whether the tank holds enough overnight. Moving off controlled load means a metering change and switchboard work, and moving back costs again, so check the numbers against your bill first. Heat pump systems shift the sums, and many owners run those on a daytime timer instead.
How do I get controlled load added, changed, or removed?
Any controlled load change involves two parties: your retailer, who is responsible for the metering, and a Level 2 ASP, who does the switchboard work.
- Start with your retailer. Controlled load has to be available on your plan and at your address. The retailer confirms the tariff and arranges the meter.
- Get the switchboard side handled. The appliance needs its own circuit, its own breaker, and space on the board. On older installations it may not exist yet.
- Clear anything blocking the meter. If the board is full or unsafe, or the consumer mains are undersized, that is quoted first. A switchboard upgrade often happens in the same visit.
- Confirm it is switching. Check over the next day or two that the tank is heating.
Costs vary too much to quote blind. The metering change depends on your retailer's plan, and the electrical work on the state of your board, so it is quoted on site.
Frequently asked questions
Is controlled load the same as off-peak?
In practice, yes. Off-peak is the older name and controlled load is the term retailers use now. Both describe a separate circuit for one appliance that the network switches on during set windows, billed at a lower rate than general usage. You may still see the old wording on an existing meter box.
Can I run my hot water whenever I want if it is on controlled load?
Not by default. The circuit is only live during the windows the network sets, so the appliance cannot heat outside them. Some installations have a boost switch that heats the tank straight away, but energy used while boosting is billed at your normal rate.
Does controlled load actually save money?
The rate per unit is lower than general usage, so for an appliance that suits it, controlled load is normally cheaper to run. Whether it is best for your home depends on your tank size and whether you have solar. If you export a lot, heating during the day can be the better result.
Who can connect a controlled load circuit in Sydney?
The metering side has to be done by an accredited Level 2 ASP, and the metering change is arranged by your electricity retailer. A standard licensed electrician can work on the circuit inside your property but cannot touch the meter or the service connection. DM Electrical holds Level 1 and Level 2 ASP accreditation and covers both sides.
The bottom line
Controlled load is a cheap way to run one big appliance, provided you let the network decide when it runs. For a storage hot water tank that is a fair trade, and most Sydney homes with electric hot water are already on it. It matters when the hot water goes cold for no reason, when a meter changeover is booked, or when solar changes the maths. If that is you, get in touch.