Common Gas Geyser Problems & How to Fix Them

Gas geysers are reliable and energy-efficient, but like any appliance, they can develop faults over time. Understanding the most common gas geyser problems and knowing when you can troubleshoot them and when you need a certified technician helps you stay safe while keeping your hot water system running efficiently. Below we break down the top issues, their causes, and practical solutions.

1. Gas Geyser Not Igniting

When a gas geyser won’t ignite, the issue typically comes from one of these causes:

Common Reasons

  • Empty or low gas cylinder

  • Blocked burner or nozzle

  • Weak or dead batteries in the ignition system

  • Insufficient water pressure

  • Faulty ignition sensor

How to Fix It

  • Replace the gas cylinder or ensure the valve is fully open.

  • Check and replace the ignition batteries.

  • Clean dust or debris from the burner area (if the manufacturer allows basic cleaning).

  • Make sure taps are opened fully to trigger the ignition.

  • If the unit still doesn’t ignite, call a certified gas technician.

2. Gas Geyser Low Pressure – Why It Happens & How to Fix It

Low water pressure stops the geyser from activating because it cannot reach the minimum flow rate.

Causes

  • Blocked filters or strainers

  • Municipal low-pressure supply

  • Lime or scale buildup inside the pipes

  • Faulty diaphragm inside the geyser

Solutions

  • Clean the inlet filters.

  • Ensure all taps are fully open.

  • Install a booster pump if you live in a low-pressure area.

  • Have a technician inspect or replace the diaphragm.

3. Overheating or Sudden Temperature Fluctuations

Causes

  • Incorrect temperature settings

  • Blocked flue or ventilation issues

  • Faulty thermostat

  • Inconsistent gas flow

Fixes

  • Set the temperature between 38°C–55°C.

  • Ensure proper ventilation (no blockages).

  • Avoid using multiple taps at once with a small-capacity geyser.

  • Have a technician check gas pressure and thermostat accuracy.

4. Gas Smell or Leaks

Warning

If you smell gas, turn everything off immediately. Do NOT attempt repairs.

What to Do

  • Turn off the gas supply at the cylinder.

  • Open all windows and ventilate the area.

  • Keep flames, cigarettes, and sparks away.

  • Call a registered gas technician urgently.

5. Geyser Ignites but Doesn’t Stay On

Possible causes

  • Faulty flame sensor

  • Blocked burner

  • Incorrect gas pressure

  • Loose wiring or damaged igniter

Possible Fix

  • Replace ignition batteries

  • Clean burner ports

  • Ensure gas regulator is functioning

  • If it continues, call a professional for a diagnostic test

Safety Warnings You Should Never Ignore

  • Never attempt internal repairs without certification

  • Always ensure proper ventilation

  • Never cover the geyser or block airflow

  • Only use SANS-approved equipment

  • Install carbon monoxide detectors where possible

Improper gas repairs can be extremely dangerous. When in doubt, stop and call a professional.

When to Call a Certified Gas Technician

Call a professional immediately if you notice:

  • Strong gas smell

  • Yellow/orange flames instead of blue

  • Geyser overheating

  • Persistent ignition failures

  • Water leakage near the unit

  • Irregular flame behaviour

A certified technician ensures compliance, safety, and long-term system performance.