No hot water from a gas heater
What you see
The tap runs cold, the burner doesn't light, or it lights and goes out.
Likely causes
The gas valve is closed or the cylinder is empty, the water flow is too low to start the heater, the ignition batteries are flat on battery models, or the flame sensor, water valve or gas valve is faulty.
Safe to try
Check the gas valve is open and the cylinder isn't empty, open the hot tap fully, and replace the ignition batteries if your model uses them.
Technician
A qualified gas technician checks the ignition, flame sensor, water valve and gas valve, and the flue.
