RV Water Heater Not Working on Electric or Gas: Fix It

You've arrived at a campsite, connected the caravan to mains power, opened the LPG bottle and switched on the water heater. There's no click, no burner, no warmth and no useful error indication. You try electric mode, then gas mode again, but the result is the same: cold water.

When an RV water heater isn't working on electric or gas, don't assume the element and burner have failed together. A shared control supply, water-flow problem, isolation switch, fuse or safety lockout can disable both heating paths. In Australia, there's also a more serious possibility. Some dual-fuel heaters have been linked to dangerous gas-mode faults, so safety checks must come before enthusiastic troubleshooting.

Why Dual-Fuel RV Water Heaters Fail on Both Power Sources

A dual-fuel heater can lose both heating modes even when the electric element and gas burner are healthy. The two systems use different heat sources, but they often share the tank, control board, 12-volt supply, water-flow conditions and safety controls. A fault in one shared condition can leave you with cold water from either mode.

Start with the conditions that allow the appliance to run:

• Water supply: Confirm that the fresh-water tank or mains connection is supplying the caravan. Open a hot tap and check for steady flow, not a weak trickle.
• Pump and inlet path: A pump that has not primed, a closed valve or a restricted inlet can prevent the heater from detecting the operating conditions it needs.
• 12-volt control power: Many gas and combination heaters require stable 12-volt power for their controls, even when mains electricity provides the heat.
• Isolation and protection: Check the heater switch, relevant fuses, circuit protection and safety cut-outs before testing internal components.
• Gas delivery: Check the LPG bottle valve, fuel level and regulator condition. A gas supply fault explains failed gas operation, but not necessarily a simultaneous electric failure.

The sequence prevents unnecessary parts replacement. If the tank is not filling or the controls have no 12-volt supply, fitting a new element or ignition assembly will not restore heating. Use the operating checks described in this guide to using a caravan hot water system, then confirm that water, electrical supply and LPG delivery are available before investigating resets or service items.

Practical rule: When both modes fail together, test the shared conditions before testing the separate heating components.

Safety changes the decision when a gas appliance is involved. Stop using the heater if you smell LPG, see scorching, find damaged wiring, notice unusual combustion, or receive a carbon monoxide alarm. Do not open sealed gas components or keep resetting a lockout to force operation. Record the model and serial details, isolate the appliance safely and arrange inspection by a licensed gas fitter when the fault may involve combustion or gas control.

A slow recovery time does not always mean total failure. The Australian caravan hot-water servicing guidance gives approximate benchmarks of about 28 minutes for a full 14-litre tank when gas and electric operate together, about 45 minutes on gas alone and about 40 minutes on electric alone (Australian caravan hot-water servicing guidance). A noticeably slower result can indicate restricted flow, poor power, sediment, weak LPG delivery or a heating component losing performance.

Australian Safety Recalls and When to Stop Using a Faulty Heater

A no-heat complaint can be an ordinary supply fault, but gas appliances add a separate risk. In December 2020, the ACCC warned about a Suburban Recreational Vehicle water heater that could operate on electricity or gas but might produce unsafe levels of carbon monoxide when gas was used for heating. The national recall covered 18,139 units sold across Australia, manufactured between 4 April 2018 and 1 August 2019. By October 2021, the ACCC said more than 50% of those units might emit deadly, odourless carbon monoxide in gas mode, while 9,600 recalled units were still waiting for inspection, including 8,359 not registered for inspection. The recall background is summarised in this Australian caravan water-heater resource (Australian RV water-heater recall information).

That history changes the first question. Don't ask only, “Which part has failed?” Ask, “Is this heater safe to operate?” Find the model and serial information on the exterior access door if you can do so without switching the appliance on or opening sealed gas components. Owners of affected units were instructed to arrange a licensed inspection, not to continue experimenting with gas mode.

Stop using the heater immediately if:

• You smell gas or suspect a leak: Turn off the LPG supply if it's safe, ventilate the area and avoid flames, switches or anything that could create an ignition source.
• A carbon monoxide alarm activates: Leave the caravan and seek professional help. Don't silence the alarm and restart the appliance.
• The model may be recalled and hasn't been inspected: Keep both heating modes off until a licensed person checks it.
• The flue, vent or combustion area is blocked or damaged: Gas combustion needs safe ventilation and exhaust clearance.
• The heater repeatedly locks out: A recurring lockout can indicate an ignition, combustion or safety-control fault rather than a switch that needs constant resetting.

Australian guidance stresses permanent ventilation and annual servicing by a licensed gas fitter for caravan gas appliances, and advises immediate stop-use action where a leak is suspected or an affected gas-mode heater hasn't been inspected (Western Australian gas and electrical camping safety guidance). For broader cold-weather protection around water systems, SwiftJet's winter prep guide is useful, but winter preparation doesn't replace a gas-safety inspection.

For additional context on gas-capable caravan systems, see this guide to a gas hot-water heater for a caravan. The essential boundary is simple: owner checks can confirm supplies and visible controls, but they must not turn into gas-valve, burner or flue repairs.

Step-by-Step Diagnostic Sequence for No Heat on Electric or Gas

Use the least invasive checks first. This sequence separates a shared supply problem from a fault inside the heater and reduces the temptation to order parts based on one symptom.

Start with water, not the burner

Confirm that the tank is full before applying heat. Open a hot-water tap and allow the pump to run long enough to establish stable flow. If the flow surges, stays weak or stops, investigate the fresh-water level, pump prime, inlet valve, strainer and hose restrictions.

A combination unit may refuse to start when it can't detect the expected water conditions. Running a heating element against an empty tank can also damage it, so this check isn't just about convenience.

Confirm the electrical path

Check the caravan's mains connection, RCD and relevant breaker, then verify that the heater's electric switch is on. If mains power is available elsewhere but the heater remains silent, inspect the 12V control fuse and isolation switch. A flat battery or poor 12V connection can prevent the control board, relays or gas ignition system from operating.

If you're competent with electrical testing, measurements can help separate a supply fault from an appliance fault. Don't remove covers or work on live 240V components unless you're appropriately qualified.

Confirm LPG delivery without dismantling the appliance

Make sure the cylinder valve is open and there's LPG available. A stove burner can provide a basic indication that gas is reaching the caravan, but it doesn't prove the water heater has correct pressure or that its valve and ignition circuit are healthy.

Listen for the heater's normal sequence, where applicable. A click without ignition, repeated clicking with no flame or complete silence each points towards a different part of the gas path. Stop immediately if you smell gas, hear an abnormal hiss or see soot around the combustion area.

Check reset and service conditions

Once water, 12V power, mains availability and gas delivery are confirmed, look for an accessible reset or thermal cut-out specified by the manufacturer. Don't bridge, bypass or permanently defeat a safety device. If the heater trips again after resetting, treat that as evidence of an underlying fault.

Only then should a technician test the element, thermostat, anode, relief valve, burner, ignition component or gas valve. Guidance for checking an electric element is available in this resource on how to test a hot-water element, but testing inside the appliance remains subject to electrical and gas-safety limits.

Electric Heating Faults Versus Gas Heating Faults in Caravans

Electric and gas heating faults produce different clues after the shared water supply, controls and power sources have been checked. Electric mode is usually quiet, so focus on the RCD, breaker, isolation switch, heating response and water temperature. Gas mode provides more direct evidence through ignition sounds, flame behaviour, burner operation and the exhaust area.

Use the heater's normal recovery pattern as a diagnostic clue, not as a pass or fail test. Australian dual-fuel heater guidance provides useful operating benchmarks (dual-fuel caravan heater operating benchmarks), but recovery changes with starting water temperature, tank condition, supply voltage, gas pressure and demand.

If gas heats normally while electric mode is slow or cold, the shared 12V controls are probably functioning. Check the electric supply, element, thermostat, thermal cut-out and connections before replacing the element. If both modes are slow, investigate shared issues such as restricted water flow, sediment, incorrect tank filling or a supply problem. A fault affecting both modes deserves more attention than two unrelated heating faults.

Gas operation that produces clicking without ignition, a brief flame or repeated lockout points towards ignition, flame sensing, burner, gas valve or combustion conditions. Soot, unusual exhaust behaviour or signs of restricted venting are safety warnings. Do not dismantle the burner or alter the gas path to prove a theory.

Australian recall and compliance requirements make the decision straightforward when combustion safety is in doubt. Stop using the heater if you smell gas, see soot, find damaged venting, hear an abnormal hiss or experience repeated safety shutdowns. Arrange inspection by a licensed gas fitter rather than continuing to switch between heating modes. A heater that still produces hot water can remain unsafe if combustion or exhaust control has failed.

Simple Fixes and Parts to Inspect Before Calling a Technician

Some owners can resolve a no-heat complaint without opening the heater cabinet. The safe work is mostly about restoring normal conditions, not modifying the appliance.

Start with the basics:

• Restore water flow: Open the cold-water inlet fully, confirm the pump is primed and clear an accessible strainer if the manufacturer permits it.
• Reset protection once: If an accessible thermal limiter or control reset has tripped, follow the heater manual. A repeat trip means stop resetting and arrange service.
• Check the 12V fuse: Replace a blown fuse only with the specified type and rating. If it blows again, there's a fault that needs diagnosis.
• Bleed trapped air: Run the hot tap until flow becomes consistent after filling or servicing the water system. Don't run a heating cycle until the tank is properly filled.
• Inspect external connections: Look for loose plugs, damaged wiring, water leaks or corrosion around accessible areas, but leave sealed gas connections alone.

An anode and sediment also deserve attention during scheduled maintenance. Severe corrosion or buildup can reduce tank performance, affect the element and contribute to restricted water movement. Drainage, flushing and anode replacement must follow the appliance instructions, and the tank must be isolated from pressure and heat before work begins.

The pressure-relief valve should move and discharge as designed, but it isn't a component to cap, block or substitute with an incorrect fitting. A persistent leak, stiff valve or damaged seal calls for the correct replacement and a competent assessment, especially if the tank has suffered corrosion.

What doesn't work: Replacing the element first, bypassing a thermal cut-out or repeatedly cycling a locked-out gas heater. Those actions can hide the original fault and create a more dangerous one.

Use model-specific parts rather than relying on appearance. Elements, thermostats, anodes, valves, seals and flexible hoses need to match the heater and the caravan installation. Australian suppliers, including Ring Hot Water, stock caravan and RV water-system components such as heaters, pumps, elements, thermostats, flexible hoses and 12mm fittings, while gas installation and service still require the appropriate licensed trade.

When to Call a Licensed Gas Fitter or Replace the Heater

A caravan water heater that fails on both electric and gas deserves a decision about safety before a decision about parts. Stop testing and call a licensed gas fitter if the fault may involve LPG pressure, the gas valve, burner, ignition assembly, flue, ventilation or combustion. Australian caravan gas work must comply with AS/NZS 5601.2 and be completed by the appropriate licensed trade. The caravan hot-water installation requirements also need to suit the vehicle and appliance. A visual inspection may show damage, but it cannot prove safe combustion or gas tightness.

Arrange professional assessment promptly if:

• The heater may be part of the Suburban recall: Stop using gas mode until the model and serial number have been checked and the appliance inspected.
• There is a gas smell, soot, abnormal flame or combustion odour: Turn the heater off, avoid ignition sources and keep it off.
• A carbon monoxide alarm activates: Leave the caravan and obtain urgent professional assistance.
• The heater repeatedly locks out: A recurring lockout indicates that a safety control is detecting a condition requiring diagnosis.
• The RCD or circuit breaker keeps tripping: Repeated trips may indicate an insulation, wiring or element fault. Do not keep resetting the protection.
• The tank, anode area or relief valve is badly corroded: Corrosion can progress from a service issue to leakage, structural damage or an unreliable repair.

Replacement may be the better choice when corrosion has affected the tank, compatible parts are difficult to source, or faults keep returning across both fuel paths. Compare the cost and downtime of several ageing components with a compliance-certified replacement that matches the caravan's water connections, ventilation, LPG arrangement and electrical capacity.

A silent heater alone does not justify replacement. Confirm the shared controls and supplies first, then have a technician identify whether the failed component is the element, thermostat, ignition part, gas valve or safety control. Diagnosing an upstream fault protects the replacement from the same failure.

Ring Hot Water supplies caravan and RV water heaters, pumps, replacement parts and fittings for electric, LPG and combination systems, and provides Melbourne-based installation, repair and maintenance support. If both modes have failed, take the heater's model and serial details to the technician and stop at the point where gas safety or live electrical work begins.