You turn on the hot tap and... cold water. Before you call anyone, a few simple checks can help you work out whether you need an electrician, a plumber, or just patience.
Step 1: Identify Your System Type
- Electric storage — a tank (usually in a cupboard, on a wall, or outside) that heats and stores water. Most common in Sydney apartments and older homes
- Gas storage or instantaneous — uses gas to heat water. Not an electrical issue in most cases (call a gas fitter/plumber)
- Heat pump — uses a compressor unit (looks like a small AC outdoor unit) connected to a tank. Electrical system
- Solar with electric boost — panels on the roof with a tank and electric backup element. Partially electrical
Step 2: Check the Obvious Things
- Is your switchboard OK? Check if the hot water circuit breaker has tripped. In many homes, the hot water is on a dedicated circuit (often labelled "HWS" or "Hot Water"). Reset it if tripped
- Is it an off-peak system? If your hot water runs on a controlled load (off-peak tariff), it only heats at specific times (usually overnight). If you've used all the stored hot water during the day, you'll need to wait until the next heating cycle. Check with your energy provider for your off-peak hours
- Has anyone used an unusual amount of hot water? Extra guests, long showers, or running the dishwasher and washing machine simultaneously can empty a storage tank. It takes 2-4 hours for a full tank to reheat
- Is the temperature just reduced? Lukewarm water (rather than cold) might indicate a partially failed element or a thermostat issue
When It's an Electrical Problem
Call an electrician if:
- The hot water circuit breaker trips repeatedly when you reset it
- The safety switch (RCD) trips when the hot water circuit is on — this indicates a leaking element
- You have no hot water and the circuit breaker appears to be on — the element or thermostat may have failed
- Your off-peak system isn't heating even though it should be — the controlled load relay or timer may be faulty
When It's a Plumbing Problem
Call a plumber if:
- You can see water leaking from the tank or relief valve
- Hot water is rusty or discoloured
- You have hot water at one tap but not others (a mixing valve or pipe issue)
- The tempering valve is letting too much cold water mix in (output is always lukewarm)
- The tank is physically damaged or heavily corroded
Common Electric Hot Water Repairs
- Element replacement: $200–$400 (the most common repair)
- Thermostat replacement: $100–$200
- Circuit breaker/RCD repair: $150–$300
- Off-peak relay/timer replacement: $200–$400 (may involve Ausgrid)
When to Replace vs Repair
If your electric hot water system is:
- Under 10 years old: Usually worth repairing
- 10-15 years old: Repair if the tank is in good condition, but consider replacement planning
- Over 15 years old: Replacement is usually more cost-effective. Consider a heat pump for significant energy savings
Hot water problems in Sydney's Eastern Suburbs? Call Randwick Electrical on 0413 707 758 — we'll diagnose whether it's electrical or plumbing and get you sorted.