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Losing hot water is one of the most disruptive faults in a home — and in winter it always seems to happen at the worst time. Before you call anyone, there are a few quick checks that often pinpoint the problem, and sometimes fix it. Here is a step-by-step guide for electric, gas and continuous flow systems.
First, Identify Your System
The checks differ depending on what you have:
- Electric cylinder — a tank, usually in a cupboard or garage, heated by an element
- Gas storage cylinder — a tank heated by a gas burner, often outside
- Continuous flow (gas or electric) — a wall-mounted unit that heats water on demand, no tank
Not sure which suits you long term? See hot water cylinder vs continuous flow.
Electric Cylinder: What to Check
- Check the switchboard. A tripped breaker or blown fuse for the hot water circuit is a common cause. Reset it once — if it trips again, stop and call a plumber or electrician.
- Check it is switched on. Some homes run hot water on a controlled (night-rate) circuit; confirm it has not been switched off.
- Listen and feel. If the breaker is on but the water is cold, the element or thermostat has likely failed — a job for a plumber.
- Look for leaks. Water pooling under the cylinder means the tank may be failing and needs attention.
Gas Storage Cylinder: What to Check
- Check the pilot light or ignition. Older gas storage units have a pilot light that can go out. Relight it following the instructions on the unit if you are comfortable doing so.
- Check the gas supply. Confirm the gas is on, and if you are on LPG, that the bottle is not empty.
- If it will not stay lit, the thermocouple or another component may have failed — call a gasfitter.
For a deeper dive into gas systems specifically, see gas hot water not working? pilot light and califont troubleshooting.
Continuous Flow: What to Check
- Check power and gas. Continuous flow units need power for the controls and (if gas) a gas supply or a full LPG bottle.
- Look for an error code. Many units show a fault code on a controller — note it down, as it tells the plumber a lot.
- Check the water flow. These units need a minimum flow to fire up; a partly closed valve or blocked filter can stop them.
When to Call a Plumber or Gasfitter
Call for help if the breaker keeps tripping, the element or thermostat has failed, a gas unit will not stay lit, the cylinder is leaking, or you simply cannot get it going. If your cylinder is old and this is not the first problem, it may be time to replace it — see 5 signs your hot water cylinder needs replacing. And remember cylinders are most likely to fail under winter load, as we explain in why hot water cylinders fail in winter.
Hot Water Repairs Across Auckland
Water and Gas Worx repairs and replaces all hot water systems across Auckland — electric, gas and continuous flow. Lost hot water and need it back fast? Our emergency plumber service is available 24/7. See our hot water services and areas we service.
Call 0800 322 322 or email [email protected].
Frequently Asked Questions
Why do I suddenly have no hot water?
The most common causes are a tripped breaker or failed element and thermostat on an electric cylinder, a pilot light that has gone out or an empty LPG bottle on a gas unit, or a fault code on a continuous flow system. Start by checking power and gas supply before calling for help.
My hot water breaker keeps tripping — what does that mean?
Reset it once. If it trips again, do not keep resetting it — that usually points to a faulty element or an electrical fault, which needs a plumber or electrician to investigate safely. Repeated tripping is a sign something has failed, not a glitch.
Can I relight my gas hot water pilot myself?
On many older gas storage units you can, following the instructions printed on the unit. If it will not light or will not stay lit, the thermocouple or another component may have failed and you should call a registered gasfitter rather than keep trying.
How quickly can you restore my hot water?
For a loss of hot water we aim for same-day where possible, and our emergency service is available 24/7. Our rate is $155 plus GST for the first hour, then $100 plus GST per hour after that; after-hours is $295 plus GST for the first hour, and public holidays $395 plus GST for the first hour. We quote before starting.
