Gas Hot Water in Your Mars Caravan Won’t Stay Lit? Basic Checks to Try

Gas Hot Water System Won’t Stay Lit – Basic Checks

Gas Hot Water in Your Mars Caravan Won’t Stay Lit? Basic Checks to Try

If your Mars caravan’s gas hot water system won’t light, keeps going out or repeatedly shows a fault light, it can be frustrating. While gas appliances must be serviced by a licensed gas fitter, there are some simple checks you can do first.

This guide covers common causes and basic user-level checks. Always follow your specific appliance manual as the first reference.

Safety first: If you smell gas, see visible damage or feel unsure, turn the gas OFF at the bottle and contact a licensed gas fitter or Mars support.

1. Basic Questions Before You Start

Before troubleshooting, ask:

  • Is there gas in the bottle and is the valve turned on?
  • Do other gas appliances (stove) work normally?
  • Are you in a location with strong wind or very low temperatures?
  • Does the system show any error or fault lights on its control panel?

The answers to these will help narrow down the cause.

2. Confirm Gas Supply

  • Make sure the gas cylinder valve is open.
  • Check that any changeover lever on the regulator is pointing to a bottle with gas.
  • Test another gas appliance, such as the stove:
    • If the stove lights and runs steadily, gas is reaching the van.
    • If the stove will not light, you may have a wider gas supply issue.

If gas does not reach any appliance, turn everything off and have the gas system inspected by a licensed gas fitter.

3. Check 12V Power and Water Flow

Many caravan gas hot water systems need:

  • 12V power for ignition and controls.
  • Enough water flow through the system to trigger heating.
  • Ensure your 12V system is on and any relevant fuses are OK.
  • Check that the water pump is operating and there is good flow at the hot taps.

If there is very low flow, air in the lines or pump problems, the hot water unit may not operate correctly.

4. Ventilation and Exhaust Area

Gas hot water systems need adequate air and a clear exhaust path.

  • Make sure the exhaust vent outside is not covered or blocked.
  • Do not place objects, covers or awnings directly over the exhaust outlet while the unit is operating.
  • In very strong winds, the flame may blow out or the unit may go into fault.

If windy conditions are suspected, you may need to wait for calmer conditions or try to shield the exhaust area without blocking it.

5. Start-Up Sequence – Follow the Manual

Different models have different controls, but a typical start might be:

  1. Turn on the gas bottle and ensure other gas appliances work.
  2. Switch on the hot water power or control switch inside the van.
  3. Turn on a hot tap so water flows through the system.
  4. Listen for the unit attempting to ignite (clicking or fan noise).

If the unit tries to light a few times and then stops with an error light, note the light pattern or code for your technician.

6. Common Symptoms and Possible Causes

6.1 System Lights Then Goes Out Quickly

Possible causes:

  • Flame sensing issue – flame is present but not being detected correctly.
  • Strong wind blowing the flame out.
  • Low gas pressure or intermittent gas supply.

User checks:

  • Verify gas supply and bottle level.
  • Test another gas appliance for consistent performance.
  • Try again when wind is calmer.

6.2 System Keeps Trying to Ignite but Never Lights

Possible causes:

  • No gas reaching the unit.
  • Gas valve not opening correctly (requires a technician).
  • Ignition system fault (requires a technician).

User checks:

  • Confirm bottles are on and gas reaches other appliances.
  • Check 12V supply and any hot water fuses.

6.3 Fault or Error Light Displayed

Most modern hot water systems will show a light or code when they lock out.

  • Check the appliance manual for what the specific code or flash pattern means.
  • Record the code and when it occurs (e.g. “after 3 ignition attempts”).

This information is very helpful for service technicians.

7. Things You Should Not Do

  • Do not remove covers, panels or internal parts from the hot water unit unless instructed in the manual for basic user access.
  • Do not adjust gas valves, regulators or internal components – this is licensed work only.
  • Do not block vents or exhausts to try to “protect from wind” in a way that prevents proper airflow.

8. When to Call a Licensed Gas Fitter or Mars Support

Contact a licensed gas fitter or Mars Campers support if:

  • The hot water system continually fails to light or locks out with an error.
  • You suspect a gas leak or smell gas near the unit.
  • You can see obvious damage, soot or scorching near the burner or exhaust.
  • You are not comfortable performing the basic checks in this guide.

When you lodge a ticket, include:

  • Your van model and VIN.
  • The brand and model of the hot water system (from the data plate or manual).
  • A description of the symptoms (e.g. “lights for 3–5 seconds then goes out”).
  • Any error codes or light patterns observed.
  • Whether other gas appliances work normally.

Summary

A gas hot water system that won’t stay lit is usually struggling with gas supply, ignition, sensing or environmental conditions like strong wind. As the owner, you can:

  • Confirm gas is reaching the van and other appliances.
  • Check 12V power and water flow.
  • Ensure vents and exhausts are clear and not blocked.
  • Observe any error lights or patterns.

For anything beyond basic checks, a licensed gas fitter or authorised service agent should inspect and repair the system to keep it safe and reliable.