What to Do When Your Hot Water System Fails

There are few household emergencies more disruptive than losing hot water — especially first thing in the morning, or when you have a house full of people. The good news is that many hot water failures have simple causes, and knowing what to check first can save you time and money.

Here's a practical, step-by-step guide for Northern Rivers homeowners on what to do when the hot water stops.

Step 1: Check the obvious things first

Before calling a plumber, run through these quick checks. You'd be surprised how often the fix is simple.

Is the power or gas supply on?

For electric systems, check your switchboard. Hot water systems are usually on a dedicated circuit breaker — look for one labelled "hot water" or "HWS". If it's tripped, reset it and wait 30–60 minutes for the water to reheat.

For LPG systems, check whether your gas bottles are empty. If you have a gauge, check it. If not, try another LPG appliance in the house — if that's not working either, you're out of gas.

Is it just the hot water, or all water?

If you have no water at all — hot or cold — the issue is with your water supply, not your hot water system. Check whether your neighbours have water, and contact your water utility if needed.

Has there been a power outage recently?

Some electric hot water systems, particularly those on off-peak tariffs, won't reheat until the next off-peak period after a power outage. If you had an outage overnight, your system may simply need time to catch up.

Step 2: Identify your system type

The next steps depend on what type of hot water system you have. If you're not sure, look for a label or data plate on the unit itself.

Electric storage systems

If the circuit breaker is fine but you still have no hot water, the most likely culprits are:

• Failed heating element — the most common failure point in electric storage systems. The element burns out over time, especially if the tank has had sediment build-up.
• Faulty thermostat — if the thermostat fails, the element won't know when to heat.
• Pressure relief valve discharge — if the valve has been releasing water (you may notice a drip or puddle near the unit), it could indicate excessive pressure or a faulty valve.

None of these are DIY fixes — you'll need a licensed plumber or electrician.

LPG systems

If your gas supply is confirmed and the system still isn't working:

• Pilot light out — older LPG storage systems have a pilot light that can go out. Check the manufacturer's instructions for relighting it (this is usually safe to do yourself).
• Faulty burner or igniter — if the pilot won't stay lit, or the burner won't fire, you need a technician.
• Continuous flow systems — these have electronic ignition and can fail due to a flat battery in the igniter, a blocked filter, or a faulty flow sensor. Check the battery first; if that's not it, call a plumber.

Heat pump systems

Heat pumps are more complex than storage systems. If yours has stopped working:

• Check the display panel for error codes — most modern heat pumps will show a fault code that helps diagnose the issue.
• Make sure the unit has adequate airflow around it — heat pumps need to draw in ambient air to operate.
• Check that the circuit breaker hasn't tripped.

If you see an error code or can't identify the cause, call a licensed technician. Heat pump repairs are not DIY territory.

Step 3: Check for visible damage or leaks

While you're investigating, take a look at the unit itself. Look for:

• Water pooling at the base — this usually means the tank is leaking internally and needs replacement
• Rust or corrosion on the tank or fittings
• Damaged or melted wiring (electric systems)
• Discoloured or sooty marks around the burner (LPG systems) — this can indicate a combustion problem and should be treated as urgent

If you see any of these, don't attempt to use the system. Call a plumber.

Step 4: Know when it's a repair vs a replacement

This is the question most homeowners want answered. Here's a rough guide:

Repair is usually the right call when:

• The system is less than 8 years old
• The fault is a single component (element, thermostat, valve)
• There's no sign of tank corrosion or leaking

Replacement is usually the better option when:

• The system is over 10 years old
• The tank is leaking or corroding
• Repair costs are more than 50% of a new system
• You've had repeated failures in the past 12 months

A good plumber will give you an honest assessment rather than just recommending the most expensive option. If you're unsure, get a second opinion.

Step 5: Call a licensed plumber

Hot water system repairs and replacements must be carried out by a licensed plumber in NSW. This isn't just a legal requirement — it's important for safety, particularly with gas systems.

When you call, be ready to tell them:

• The type of system (electric, LPG storage, LPG continuous flow, heat pump)
• The brand and model if you can find it
• What symptoms you've noticed (no hot water, lukewarm water, leaking, noises)
• How old the system is (approximately)

This helps the plumber come prepared with the right parts and equipment, which means faster resolution for you.

What about after-hours emergencies?

Losing hot water overnight or on a weekend is genuinely disruptive, especially for families with young children. Northern Rivers Hot Water offers after-hours emergency call-outs for situations that can't wait — a burst tank, a serious leak, or no hot water with young kids in the house.

Northern Rivers Hot Water provides emergency hot water service across Lismore, Ballina, Byron Bay, Tweed Heads, Casino, and the surrounding region. Our regular hours are Mon–Thu 7am–4pm, Fri 7am–3:30pm and Sat 9am–12pm — but for genuine emergencies outside those hours, call us and we'll do our best to get to you.

If you're without hot water right now, call us on 0472 580 441. We'll get you sorted as quickly as possible.

For a full breakdown of what happens from your first call to hot water restored, read our guide on what to expect from a same-day emergency hot water repair in the Northern Rivers. You can also see the full range of hot water system repairs and installations we offer across the Northern Rivers.