During a trial for ignition in a hot surface ignition system, the igniter is not glowing, but the main gas valve is energized. Which of the following is an INCORRECT test to perform?

In a situation where the igniter is not glowing, yet the main gas valve is energized, the focus should be on understanding why the igniter is failing to activate. The question revolves around determining which test would not provide relevant information regarding the issue at hand.

Measuring the resistance of the igniter is a crucial step, as it helps determine if the igniter is functioning properly and can generate the necessary heat for ignition. This test will indicate whether the igniter is defective or open-circuited.

Checking for power at the gas valve is also important because if the gas valve receives power and opens, it suggests that the issue lies with the igniter system rather than the gas supply.

Inspecting the ignition cable for damage is relevant as well, since any damage to the cable could prevent proper function of the ignition system. Ensuring that the igniter receives the necessary voltage to operate is critical to successful ignition.

However, measuring the resistance of the limit control may not provide useful information in this specific scenario. Limit controls are designed to protect the heating system by shutting it down if temperatures exceed safe levels. If the system is energized and the igniter is not glowing, the limit control is unlikely to be the issue preventing ignition. This makes testing