The gas geyser pilot assembly explained

The parts

• Pilot jet (orifice): a tiny hole that meters gas to the pilot flame.
• Pilot tube: the thin pipe from the gas valve to the jet.
• Bracket and hood: hold everything in position and shape the flame.
• Thermocouple: sits in the flame and holds the gas valve open.
• Igniter electrode: makes the spark that lights the pilot.

A healthy pilot

Blue, steady, about the size of a fingertip, and wrapping around the upper part of the thermocouple. A yellow, tiny or lifting flame points to dirt, draught or pressure problems.

Common problems

• Blocked jet from dust, rust or insects: weak or no flame.
• Kinked or leaking pilot tube.
• Bracket knocked out of position so the flame misses the thermocouple.
• Cracked electrode so the spark jumps elsewhere.

Cleaning and service

Pilot jets are delicate; cleaning should not enlarge the hole. A technician can clean the jet and tube during an annual service. Many “faulty geyser” calls in winter turn out to be a dirty pilot.

Where auto ignition fits

The Autopilot kit bypasses the pilot entirely: it lights the main burner with its own spark, so a dirty or worn pilot assembly no longer stops the geyser starting after load shedding. The geyser’s thermostat still controls the water temperature.