A furnace with a hot surface igniter will not light. What should the technician check before replacing the igniter?

In troubleshooting a furnace with a hot surface igniter that fails to light, it's crucial to conduct a comprehensive check of several components before deciding to replace the igniter itself. Each of the checks mentioned serves an important purpose.

Investigating for loose wires is essential since poor connections can prevent the necessary voltage from reaching the igniter, rendering it unable to operate. Even a slight disconnection can disrupt the entire ignition process.

Moreover, checking the voltage to the igniter is vital because if the igniter is receiving insufficient or no voltage, it will not heat up and achieve the temperature required to ignite the gas. This test helps ascertain whether the issue lies with the power supply rather than the igniter itself.

Finally, examining the igniter for physical damage, such as cracks, can help identify if the component has failed structurally. A cracked igniter may not function, and knowing its condition is crucial before deciding to replace it.

Conducting all these checks together can aid in diagnosing the actual problem and prevent unnecessary replacement of the igniter if it's not the root cause of the issue. Hence, performing a thorough investigation of these three aspects is the appropriate approach before drawing conclusions.